What are the roots of the quadratic equation x²-81=0

Answers

Answer 1

Answer:

What are the roots of the quadratic equation x²-81=0

Answer 2

Answer:

x = ± 9

Step-by-step explanation:

Given

x² - 81 = 0 ( add 81 to both sides )

x² = 81 ( take the square root of both sides )

x = ± [tex]\sqrt{81}[/tex] = ± 9

Thus roots are x = - 9, x = 9


Related Questions

I need some help? I don't understand math at all.

Answers

Answer:

I think its 4 but not 100% sure.

264-10=16+52

Add 10 to both sides

264=16+62

subtract 16 from both sides

248=62

Divide and i got 4.

They will have the same amount after 4 weeks. We want the $$ to be equal so we write and equation that fits the information and put them to equal each other. After that it goes into the calculator. Hope this helps!!

ASAP! I will give branilest!

1. Based on the information in the table, is the cost of the apples proportional to the weight of apples? Yes/No

pounds of apples cost of apples
2 $3.76
3 $5.64
4 $7.52
5 $9.40

2. Base on the information in the table, is the cost of the pizza proportional to the number of toppings? Yes/No



number of toppings cost of pizza
2 $11.99
3 $13.49
4 $14.99
5 $16.49
3. Write an equation for the table that represents a proportional relationship.

c =
1.50 or 1.88




3A. Use the following variables to help in your equation:
Is A the answer or T


a is for pounds of apples
t is for number of toppings

Answers

Answer:

1 = No     2 = Yes      3 = 1.88

Step-by-step explanation:

Answer:

1. Yes 2. No 3. = 1.88 .

Step-by-step explanation:

1. Possibly yes, the first table represents a proportional relationship because cost per pound of apples is the same in each row, 1.88 dollars per pound.

2. Definitely no, the second table does not represent a proportional relationship because cost per topping is not the same in each row. (An equation is =1.50+8.99 but students do not need to provide an equation.)

3. An equation relating the cost to pounds of apples is = 1.88.

Need help ASAP have 30 minutes

Answers

Answer:

7.25

Step-by-step explanation:

if you want to know what 1 box would be you would divide 14.50 by 2 to get 7.25 i’m sorry if i did this wrong

The size of the left upper chamber of the heart is one measure of cardiovascular health. When the upper left chamber is enlarged, the risk of heart problems is increased. The paper "Left Atrial Size Increases with Body Mass Index in Children" (International Journal of Cardiology [2009]:1-7) described a study in which the left atrial size was measured for a large number of children age 5 to 15 years. Based on this data, the authors concluded that for healthy children, left atrial diameter was approximately normally distributed with a mean of 26.4 mm and a standard deviation of 4.2 mm.Approximately what proportion of healthy children has left atrial diameters less than 24 mm?Approximately what proportion of healthy children has left atrial diameters greater than 32 mm?Approximately what proportion of healthy children has left atrial diameters between 25 and 30 mm?For healthy children, what is the value for which only about 20% have a larger left atrial diameter?

Answers

Answer:

so you need the value for the 20% right ?

Step-by-step explanation:

Joaquin made four times as many goals as daniel during soccer practice today. What is the ratio?

Answers

Answer:

4:1

Step-by-step explanation:

Let the no. of goals Daniel scored be x

Hence,

No. of goals Joaquin scored = 4 x

No. of goals Daniel scored = x

Hence,

The ratio of the no. of goals scored by Joaquin to the no. of goals scored by Daniel

[tex]=\frac{4x}{1x}[/tex]

[tex]=\frac{4}{1} \\=4:1[/tex]

PLEASE HELP ME!!
It’s due in a couple of hours and I’m having hard time understanding how to do these problems. It’s 40 points, 10 for each problem.

Answers

Answer:

11. f(g(3))=5 g(f(-2))=-6

12.f(g(3))=8 g(f(-2))=3

13.f(g(3))=8 g(f(-2))=3

14.f(g(3))=0  g(f(-2))=5

Step-by-step explanation:

drag numbers to write an equation for the line in slope intercept form number is may be used once more than once or not at all

Answers

Answer:

y = -4x + 5

Step-by-step explanation:

The equation for the line, in slope-intercept form will take the following equation format which is y = mx + b.

Where,

b = y-intercept = 5 (this is where the line intercepts the y-axis, and also, x = 0 here)

m = [tex] \frac{y_2 - y_1}{x_2 - x_1} [/tex]

Use any two points on the line. Using (0, 5) and (1, 1), calculate m as follows:

m = [tex] \frac{1 - 5}{1 - 0} = \frac{-4}{1} = -4 [/tex]

Substitute m = -4, and b = 5 into y = mx + b.

y = -4x + 5

Answer:

Y=-4x+5

Step-by-step explanation:

Pls help i dont understand :( will give Brainliest + 25 Points

Answers

Answer:

A

Step-by-step explanation:

plug the points into the slope formula

slope = (y2 - y1)/(x2 - x1)  Then you get the slope of -0.5

(5 - -1))/(-6-6)

6/-12

-0.5

Plug a point in to the equation of y = -0.5x + b

-1 = -0.5(6) +b

2 = b

faud's model racing care drives an average speed of 3 feet per second. Fuad records the distance and times in a table. At this rate, how long will it take the car to travel 21 feet?

Answers

Answer:

well 3 × 7 = 21

Step-by-step explanation:

1. 0+3=3

2. 3+3=6

3. 6+3=9

4. 9+3=12

5. 12+3=15

6. 15+3=18

7. 18+3=21

So the answer is 7

hi, what is 1+1 and 2+3​

Answers

Answer:

1+1 is 2 and 2+3 is 5

Step-by-step explanation:

can someone help me solve please.. thanks..

Answers

Answer:

see below

Step-by-step explanation:

f(0) means x=0

We use the f(x) when x<5

f(0) = 0+4 = 4

f(6) means x=6  

We use the f(x) when 5≤x<7

f(6) =8

The number 80 is decreased to 73. What is the percentage by which the number was decreased, to the nearest tenth of a percent?

Answers

Answer:

8.75 as 80-73 gives 7 and 7/80x 100= 8.73 by which is the percentage it is decreased.

pls do this i’ll give brainliest!!

Answers

Answer:

7. move to the right by 4 units and down by 5 units

8. just rotate it to the left side (180 degrees is a flat line in the opposite direction)

9. reflection is pretty easy, just pretend you are folding your paper in half. so just redraw it on the other side in the opposite direction (fold paper sideways)

Step-by-step explanation:

Miguel gave 5 items to the clerk at the store. Before taxes were added the total was 36.00. If each item was priced the same, what is the cost of one of the items?

Answers

Answer:

$7.20

Step-by-step explanation:

$36.00 for 5 items.

Divide $36.00 by 5 to find the price of 1 item.

$36/5 = $7.20

PLEASE ANSWER REALLY QUICK PLEASE?!?!?!?!

Answers

Answer:

12x -11

Step-by-step explanation:

Lets start by applying the 2/3 to the two values in the parenthesis. Doing so will yield: 4x -7 +8x -4. We can simplify this to be 12x -11

12x -11 is correct answer

Can someone explain both of these ratios and answers to me?

Answers

Answer:

15 ( for Herimone) And 8 ( For Stranger Things)

Step-by-step explanation:

When Herimone uses 5 grams of Pearl Sheen she creates 30 fluid ounces of love potion. Last week she created 90 ounces which is 3 times larger than 30 ounces so you have to multiply 5 by 3 to figure out the amount of Pearl Sheen she used which is 15

For stranger things they Multiplied 3 by 2 so you have to multiply 1 by 2 to get 2. Then you have to add 6 and 2 to get 8 kids.

Hope This Helps!

The formula = 21+ 2m is used when calculating:
a area of a rectangle
C area of a circle
b. perimeter of a rectangle
d circumference of a circle

Answers

I’m pretty sure it’s B) perimeter of a rectangle, I’m sorry if it’s wrong

FIRST RIGHT GETS BRAINLIEST

Answers

Answer:

0?

Step-by-step explanation:

Answer 4
Because it is going down up by 2 ( if you are looking right to left)

2. What is the rule that relates values from a set of
values to a second set of values?
A. Function
C. Relation
B. Theorem
D. None of these​

Answers

Answer:

Relation

Step-by-step explanation:

The rule that relates elements of one set to elements of another set is called "Relation". Functions are special types of Relations.

The body of 150lb person contains 2.3x10-4 lbs of copper. How much copper is contaned

Answers

19 I think. If you use a calculator and calculate it you get 19.

We would like to know the velocity of the block when it reaches some position x. Finding this requires an integration. However, acceleration is defined as a derivative with respect to time, which leads to integrals with respect to time, but the force is given as a function of position. To get around this, use the chain rule to find an alternative definition for the acceleration ax that can be written in terms of vx and dx/ dx.

Answers

Answer:

An alternative definition for the acceleration ax that can be written in terms of [tex]v_x[/tex] and [tex]\frac{dv_x}{dx}[/tex] is [tex]a_x=v_x \frac{dv_x}{dx}[/tex]

Step-by-step explanation:

We know that :

[tex]a_x=\frac{dv_x}{dt}[/tex]

Now we are supposed to find an alternative definition for the acceleration ax that can be written in terms of [tex]v_x[/tex] and [tex]\frac{dv_x}{dx}[/tex]

So, We will use chain rule over here :

[tex]a_x=\frac{dv_x}{dt}\\a_x=\frac{dv_x}{dt} \times \frac{dx}{dx}\\a_x=\frac{dv_x}{dx} \times \frac{dx}{dt}\\a_x=\frac{dv_x}{dx} \times \frac{dx}{dt} [\frac{dx}{dt}=v_x]\\a_x=\frac{dv_x}{dx} \times v_x\\a_x=v_x\frac{dv_x}{dx}[/tex]

Hence an alternative definition for the acceleration ax that can be written in terms of [tex]v_x[/tex] and [tex]\frac{dv_x}{dx}[/tex] is [tex]a_x=v_x \frac{dv_x}{dx}[/tex]

The alternative definition for the acceleration ax that can be written in terms of vx and dx/ dx is [tex]a_x = v_x \frac{dv_x}{dx}[/tex]

Chain rule:

Here we used the chain rule:

It is the basic method for differentiating a composite function. Here the first factor on the right, Df(g(x)), represents that the derivative of f(x) is first found and then x, wherever it arises, is replaced by the function g(x).

So,

[tex]a_x = \frac{dv_x}{dt}\\\\ = \frac{dv_x}{dt} \times \frac{dx}{dx}\\\\= \frac{dv_x}{dx} \times \frac{dx}{dt}\\\\ = \frac{dv_x}{dx} \times \frac{dx}{dt} (\frac{dx}{dt} = v_x)\\\\ = \frac{dv_x}{dx} \times v_x\\\\= v_x\frac{dv_x}{dx}[/tex]

Learn more about time here: https://brainly.com/question/11325462

Please Help Due Soon!

Answers

y = 1/3x +b

1 = 1/3(9) +b

1 = 3 +b

subtract 3 from both sides

-2 = b

y = 1/3x - 2

16. Mrs. Hunneycutt makes dog sweaters. Her profit each month is a function of the
price she charges for each sweater. Her total profits, y (in hundreds of dollars), based
on the sales price, x, can be modeled by the function y=-3x2 + 39x - 108.
Identify any zeros of the function, and interpret what the zeros mean in terms of the
situation

Answers

Answer:

The total profits will be zero at sales prices of $4 and $9

Step-by-step explanation:

∵ The function is y = -3x² + 39x - 108, where

y is the total profits of hundreds of dollars x is the sales price

The zeroes of the function are the values of x at y = 0

→ To find the zeroes of the function above equate y by 0

∵ 0 = -3x² + 39x - 108

→ Switch the two sides

∴ -3x² + 39x - 108 = 0

→ Divide all terms by -3 to simplify the equation

x² - 13x + 36 = 0

→ Let us factor the trinominal into two brackets

∵ The last term is +ve and the middle term is -ve

∴ The two brackets have (-) sign in the middle ⇒ (... - ...)(... - ...)

∵ x² = (x)(x)

∵ 36 = (4)(9)

∵ (4)(x) + (9)(x) = 4x + 9x = 13x ⇒ the value of the middel term

→ That means the factors of the trinomial are (x - 4) and (x - 9)

x² - 13x + 36 = (x - 4)(x - 9)

→ Replace the trinomial by its factors

(x - 4)(x - 9) = 0

→ Equate each bracket by 0 to find x

∵ x - 4 = 0

→ Add 4 to both sides

x = 4

∵ x - 9 = 0

→ Add 4 to both sides

x = 9

The zeroes of the functions are 4 and 9

∵ x represents the sales price in dollars

∴ The sales prices which make zero profit are $4 and $9

The total profits will be zero at sales prices of $4 and $9

48 on shelves how many on 12 shelves ​

Answers

Answer:

Step-by-step explanation:

If there are 48 books on shelves

Then number of books in 12 shelves

= 48 ÷ 12 = 4 books

Answer:

576

Step-by-step explanation:

because 48 books on each shelves 48×12=576

PLEASE I WILL MARK BRAINLIEST

Answers

Answer:

16 times

Step-by-step explanation:

i could give an explanation if needed

prin ce insusiri se remarca sfantul si dreptul simeon

Answers

Answer:

Nu știu scuze

Step-by-step explanation:

A box measures 4 inches by 2 inches by 6 inches .Find the volume of the box in cubic centimeters

Answers

Answer:

121.92 cm cubed

Step-by-step explanation:

all you have to do is multiply all 3 measurements to find the simple shapes volume, and then convert to centimeters using the simple 2.54 cm=1 in conversion rate

Answer:

1/36 cubic ft

Step-by-step explanation:

4 inches = 12/3 inches = 1/3 ft

2 inches = 12/6 inches = 1/6 ft

6 inches = 12/2 inches = 1/2 ft

Harold had a summer lemonade
stand where he sold small cups for
$1.25 each and large cups for $2.50
each. He made $265. If Harold sold
88 small cups, find the number of
large cups he sold.
The basketball team scored a total

Answers

Answer:

62 large cups were sold

Step-by-step explanation:

88*1.25=110

265-110=155

155/2.50=62

Which models show the problem 4/6 : 2/6 = 2? Check all that apply :​

Answers

Answer: 1st, 2nd, and 3rd option are correct :) ✨

Step-by-step explanation:

Answer:

A, B, C

Step-by-step explanation:

7t - 4 = 10t + 14 HURRY PLEASE

Answers

Answer:

7t-4=10t+14

7t-10t=14+4

-3t=18

-3t/3=18/-3

t=-6

Answer:

Pretty sure it's t = -6

Step-by-step explanation:

7t - 4 = 10t + 14

7t -10t = 14 + 4

-3t = 18

t = -6

Other Questions
A line has a slope of 1/4 and passes through the point (0.2. 4/5).Find the value of b, the y-intercept.b= Which describes an object in projectile motion?A. Gravity acts to push the object sideways.B. The object moves in a straight path.C. The forward velocity of the object is 0 m/s.D. The objects inertia carries it forward. Why is there a skeleton bride next to Rivera? When the UAE was formed on 2 December 1971 the Trucial Oman scouts were named the ____________________ANSWER THIS ONLY IF U KNOW A flea, usually less than an eighth of an inch long, can long jump about eight inches. If humanscould jump in proportion to the flea, it would only take nine leaps to go one mile! At this rate, howmany leaps would it take a human to travel 693 miles from Louisville, Kentucky to Norfolk,Virginia? help please i have 1 hour This is what I meant to ask lol If you were King Acrisius,woul you the same thing just to escape from him deadful part? The coordinates of A are (1,1) and the coordinates of B are (-5,-1)what are the coordinates for the midpoint of line segment AB? Which of the following would not be a good supporting sentence for a cause-and-effect paragraph that begins with this topic sentence:There are many causes of automobile accidents.O A. Another big cause of automobile accidents is falling asleep at thewheel.B. Automobile accidents are also caused by drinking and driving.C. We must do something about the high rate of automobileaccidentsD. One major cause is distractions. what conflicts were caused by westward expansion Why is the Dead Sea not actually a sea, and what kind of body of water is it? Find the simple interest and the total amount after two years.Principal = 2500=2500equals, 2500 rupeesAnnual rate of interest = 9 \%=9%equals, 9, percentTotal interest ==equals rupeesTotal amount ==equals rupees Who are the current justices and how long have they been serving on the Supreme Court? Give as many details as possible. solve for the perimeter What idea was outlined in the Virginia Plan?A. Having a two-house legislature that would choose a president whowould serve for lifeB. Having a national government that would be almost totallycontrolled by the statesC. Having a two-house legislature that would choose a president andSupreme Court justicesD. Having the United States and Great Britain unite once more COLOR THEMEa Q ZOOMThe Boston Tea Party, the Intolerable Acts, and the Townshend Acts all were majorcontributing factors to Read the following passage. Which early river valley civilization does it describe? This African civilization relied on the Nile to provide water for its crops. It brought water from the river to its fields through sophisticated irrigation systems. It also grew wealthy by controlling trade between central and northern African civilizations. A. Akkadia B. Sumeria C Nubia D. EgyptI need asap I chose Egypt as the correct answer can you tell me, if my answer is correct The Earths ________________ on its ________ causes day and night. ________ is measured in units of distance per unit of time.Question 2 options:VelocitySpeedForceDistance