Im very stuck lol...

b²-4ac is the discriminant (D)!

you use it when you have a second degree function and want to find the x. If:

D<0 -> no x that we can find

D=0 -> 1 answer for x

D>0 -> 2 answers for x

when your D is = or > 0 then you use these formulas to find the x:

x1= (-b-VD)/2a

x2= (-b+VD)/2a

example1:

f(x)=2x²+3x+4=0

D= b²-4ac

= 3²-4×2×4

=9- 32

=-23

-> no answers for x

example2:

f(x)=2x²+5x+2=0

D= 4²-4×2×2

= 25-16

=9

x1= (-b-VD)/2a

= (-5-3)/4

= -8/4

=-2

x2= (-b+VD)/2a

= (-5+3)/4

=-2/4

=-1/2

Answer:

The roots are 0.5 and 4.

Step-by-step explanation:

-2x^2+9x=4

Rearrange:

-2x^2 + 9x - 4 = 0

x = [-b +/- √(b)^2 - 4ac)] / 2a

Using this quadratic formula the solution is:

x = [-9 +/- √(9)^2 - 4*(-2)*(-4)] / (2*-2)

   = (-9 +/- √49) / -4

   = 9/4 +/- (-7/4)

   = 9/4 - 7/4 = 0.5

and 9/4 + 7/4 = 4

Answer:

0.17 (rounded)

Step-by-step explanation:

There's only one way a 1 can appear on a number cube out of 6 possible sides. Thus, the theoretical probability of the number cube showing a 1 is 1/6, or 0.17 rounded.

Answer:

[tex]\sqrt{\frac{x}{2} }[/tex]

Key:

• [tex]\frac{\sqrt{a}}{\sqrt{b}}=\sqrt{\frac{a}{b}}[/tex]

Step-by-step explanation:

[tex]\frac{\sqrt{x}}{\sqrt{2}}\\[/tex]

[tex]\frac{\sqrt{x}}{\sqrt{2}}=\sqrt{\frac{x}{2}}\\[/tex]

[tex]=\sqrt{\frac{x}{2}}[/tex]

Answer:

A = l x b

Step-by-step explanation:

Area = length x breath

So find the area and length and work it out by dividing area by length.

it would be 45 minutes

Answer:

14.5 Meters

Step-by-step explanation:

1 centimeter= 0.01 Meters

1450 cm x 0.01 =14.5

Answer:

x < -4

Step-by-step explanation:

-7x>28

7x<-28

x<-4

please give brainliest!

hope this helps :)

========================================================

Reason:

Ari hasn't considered the case of "red and yellow" which is almost identical to "yellow and red".

It helps to lay out a two by two table. Along the rows and columns, you'll have "red" and "yellow". See below.

Then inside the table are the list of all outcomes in the form (x,y) where x is the horizontal component along the columns, and y is the vertical component along the rows.

Example: if x = red and y = red, then we have the outcome (x,y) = (red, red)

As the table shows, we have 4 outcomes. Therefore the probability of getting two yellows is 1/4

Technically the (red, yellow) = (yellow, red) since ultimately order doesn't matter in this case. For some probability problems, order will matter. But again, order doesn't matter here and it means that we can treat these two situations the same. So I can see why Ari thinks there are only three outcomes.

--------------------------------

Here's another way to look at it:

The probability of landing on yellow is 1/2 assuming red and yellow are equally likely.

This means the probability of two yellow in a row is (1/2)*(1/2) = 1/4

Each is spin is independent of any other.

First of all we will understand the question!!

The question is saying that you are given a function and you have to find the value of x which will give the maximum profit... Lets solve it by finding the extrema using the vertex

[tex] \rm \: p(x) = - 5 {x}^{2} + 30x + 8[/tex]

[tex] \rm \: p(x) = { - 5x}^{2} + 30x + 8 \\ \rm \: a = - 5 \: and \: b \: = 30[/tex]

[tex] \rm \: x = \frac{30}{ 2 \times (- 5)} [/tex]

[tex] \rm \: x = 3[/tex]

A quadratic equation is in the form of ax²+bx+c. It took 3seconds for the golf ball to reach the green.

A quadratic equation is an equation whose leading coefficient is of second degree also the equation has only one unknown while it has 3 unknown numbers. It is written in the form of ax²+bx+c.

A.) The time that the ball takes to reach the green can be found by equation the equation against zero. As the ball will have 0 height when it will be on the green,

t²+4t-21=0

t²+7t-3t-21=0

t(t+7)-3(t+7)=0

(t+7)(t-3)=0

t = -7, 3

Hence, it took 3seconds for the golf ball to reach the green.

B.) Since the time can not be negative the second value is wrong.

Learn more about Quadratic Equations:

https://brainly.com/question/2263981

#SPJ1

Answer:

[tex]\frac{3}{22}[/tex]

Step-by-step explanation:

the bar above 36 means that the digits 36 are being repeated

we require 2 equations with the repeating digits placed after the decimal point.

let x = 0.13636.. ( multiply both sides by 10 and 1000 )

10x = 1.3636... (1)

1000x = 136.3636... (2)

subtract (1) from (2) thus eliminating the repeating digits

990x = 135 ( divide both sides by 990 )

x = [tex]\frac{135}{990}[/tex] = [tex]\frac{3}{22}[/tex] ← in simplest form

Answer:

7/23

Step-by-step explanation:

Each answer is 1.5/23 less than the previous

17/46  - 1.5/23 =   17/46 - 3/46 = 14/46 = 7/23

Answer:

S=6a^2

S=6×2^2

S=6×4=24

The right answer is C

Answer:

24 units²

Explanation:

The surface area of cube is 6(side)²

Here given:

a = 2

The surface area:

= 6(2)^2

= 6(4)

= 24

Answer:

11 students are present and 9 are absent.

The perimeter and area of the equilateral, isosceles and right angled triangle are  16.2mm 12.6mm², 15.2in and 9.61in², 21.47yds and 16.81yds² respectively.

Note that:

The perimeter of an Equilateral triangle is expressed as P = 3a

The area of an Equilateral triangle is expressed as A = ((√3)/4)a²

Where a is the dimension of the side.

The perimeter of an Isosceles triangle is expressed as P = 2a + b

The area of an Isosceles triangle is expressed as A = (ah)/2

Where b is the slant height, a is the dimension of the base and h is the height.

The perimeter of a Right angled triangle is expressed as P = a + b + c

The area of a Right angled triangle is expressed as A = (ab)/2

Where a and b is the dimension of the two sides other than the hypotenuse and c is the hypotenuse.

For the Equilateral triangle.

Given that;

Perimeter P = 3a

P = 3 × 5.4mm

P = 16.2mm

Area A = ((√3)/4)(5.4mm)²

A = ((√3)/4)( 29.16mm² )

A = 12.6mm²

The Perimeter and Area of the Equilateral triangle are 16.2mm 12.6mm² respectively.

For the Isosceles triangle.

Given that;

Perimeter P = 2a + b

P = 2(b) + a

P = 2(5.9in) + 3.4in

P = 11.8in + 3.4in

P = 15.2in

The height h is the imaginary line drawn upward from the center of a.

First, we calculate the height using Pythagorean theorem

x² = y² + z²

Where x = b = 5.9in, y = a/2 = 3.4in/2 = 1.7in, and z = h

(5.9in)² = (1.7in)² + h²

34.81in² = 2.89in² + h²

h² = 34.81in² - 2.89in²

h² = 31.92in²

h = √31.92in²

h = 5.65in

Now, the area will be;

A = (ah)/2

A = (3.4in × 5.65in )/2

A = 19.21in²/2

A = 9.61in²

The Perimeter and Area of the Isosceles triangle are 15.2in and 9.61in² respectively.

For the Right angled triangle.

Given that;

Perimeter P = a + b + c

P = 8.2yds + 4.1yds + 9.17yds

P = 21.47yds

Area A = (ab)/2

A = ( 8.2yds × 4.1yds)/2

A = ( 33.62yds²)/2

A = 16.81yds²

The Perimeter and Area of the Right angled triangle are 21.47yds and 16.81yds² respectively.

Therefore, the perimeter and area of the equilateral, isosceles and right angled triangle are  16.2mm 12.6mm², 15.2in and 9.61in², 21.47yds and 16.81yds² respectively.

Learn more about Pythagorean theorem here: brainly.com/question/343682

#SPJ1

Answer:

  2,592,100 m³

Step-by-step explanation:

The volume of the pyramid can be found by using the given dimensions in the formula for the volume of a square pyramid.

__

  V = 1/3s²h

where s is the side length of the square base, and h is the height.

Using the given dimensions, s = 230 m, h = 147 m, we find the volume to be ...

  V = 1/3(230 m)²(147 m) = 2,592,100 m³

The volume of the pyramid is 2,592,100 cubic meters.

Solve for t in terms of y :

[tex]y = t - 2 \implies t = y + 2[/tex]

Substitute this into the parametric equation for x :

[tex]x = (3t + 2)^2 \implies x = (3(y + 2) + 2)^2 \implies \boxed{x = (3y+8)^2}[/tex]

Answer:

30 degrees

Explanation:

Let the ratio's be in x, 2x, 3x

Total Interior Angle of a triangle sum ups to 180°

The smallest angle which is x is 30°

Answer:

[tex]\textsf{Length}=0.8x^2-0.7x+0.7\quad \sf units[/tex]

Step-by-step explanation:

Area of a rectangle = width × length

Therefore, to find the length of the rectangle, we need to divide the area by the width.

Using long division:

[tex]\large\begin{array}{r}0.8x^2-0.7x+0.7\phantom{)} \\x+0.5{\overline{\smash{\big)}\,0.8x^3-0.3x^2+0.35x+0.35\phantom{)}}}\\-~\phantom{(}\underline{(0.8x^3+0.4x^2)\phantom{-b))))))))))))))}}\\0-0.7x^2+0.35x+0.35\phantom{)}\\ \underline{-~\phantom{()}(-0.7x^2-0.35x)\phantom{-b)))))}}\\ 0.7x+0.35\phantom{)}\\\underline{-~\phantom{()}(0.7x-0.35)}\\ 0\phantom{)}\end{array}[/tex]

Therefore, the length of the rectangle is:

[tex]0.8x^2-0.7x+0.7[/tex]

The statement which is true is the airplane reaches its maximum height of 81 feet in 12 seconds.

Since the height of the plane is a function given by a parabola, we need to know the equation of a parabola in vertex form

The equation of a parabola with vertex (h,k) is given by y = a(x - h) + k

Since the height (in feet) of the airplane as a function of time (in seconds after the timer was started) is given by the equation h(t) = −(t − 12) + 81

So, the statement which is true is the airplane reaches its maximum height of 81 feet in 12 seconds.

Learn more about equation of a parabola in vertex form here:

https://brainly.com/question/17684824

#SPJ1

The expression that is equivalent to √10 / (4√8) is given as √5 / 8

An equation is an expression that shows the relationship between two or more variables and numbers.

Given the equation:

√10 / (4√8)

Simplifying:

= √10 / (4√(4 * 2))

= √10 / (8√2)

= √5 / 8

The expression that is equivalent to √10 / (4√8) is given as √5 / 8

Find out more on equation at: https://brainly.com/question/2972832

#SPJ1

Answer:

see the attachment photo!

Answer: [tex]18^{\circ}[/tex]

Step-by-step explanation:

In triangle RUV, angle RUV is a right angle (and thus measures 90 degrees), and angle RVU measures 72 degrees.

Since angles in a triangle add to 180 degrees, angle VRU measures

The wheat production of both farms will approach a stable amount as the years pass.

An exponential function is one that is steadily increasing or decreasing. We can see that in this case there is a positive sign indicating an increase.

Thus, from the graph, we can see that, the wheat production of both farms will approach a stable amount as the years pass.

Learn more about exponential function:https://brainly.com/question/11487261

#SPJ1

Answer:

  D.  10 square units

Step-by-step explanation:

The area of a triangle is given by the formula ...

  A = 1/2bh

__

This triangle has a base of 4 units and a height of 5 units. (These dimensions can be counted from the graph, or found by subtracting coordinate values.) Its area is ...

  A = 1/2(4 units)(5 units) = 10 square units

_____

Additional comment

The first two coordinates lie on the line x=0. The length of that segment is the difference of the y-values: 4 -(-1) = 5.

The first and last coordinates lie on the line y=-1. The length of that segment is the difference of the x-values: 4 -0 = 4.

Answer:

$122.88

Step-by-step explanation:

the phone decreases by 20% each year , that is

(100 - 20)% = 80% = [tex]\frac{80}{100}[/tex] = 0.8

the phone reduces by a factor of 0.8 each year , then after 4 years

value = $300 × [tex](0.8)^{4}[/tex] = $122.88

Answer:

36

Step-by-step explanation:

[tex]\angle AOC[/tex] is made up of s + r, and since r is [tex]\frac{3}{5}[/tex] of [tex]\angle AOC[/tex] we know r must be the remaining [tex]\frac{2}{5}[/tex] of [tex]\angle AOC[/tex].

We can solve for [tex]\angle AOC[/tex] by using this equation:

[tex]\frac{2}{5}\angle AOC = 24\\(\frac{2}{5}\angle AOC)\frac{5}{2} = (24)\frac{5}{2}\\ \boxed{\angle AOC = 60}[/tex]

1. 2 fifths of  [tex]\angle AOC[/tex] is 24

2. multiply both sides by [tex]\frac{5}{2}[/tex] to isolate [tex]\angle AOC[/tex]

3. [tex]\angle AOC[/tex] is 60°

We can now solve for r

[tex]r = \frac{3}{5}\angle AOC\\r = \frac{3}{5}(60)\\\boxed{r = 36}[/tex]

1. the equation the problem gave us

2. substitute [tex]\angle AOC[/tex] for 60 (we solved for it before)

3. [tex]r[/tex] is 36°