System practice problems
Looking at the first system of equations,
16x - 10y = 10
-8x - 6y = 6
If we multiply both sides of the second equation by 2, the coefficient of x is exactly the negative of the coefficient of x in the first equation.
-8x - 6y = 6
⇒ 2 (-8x - 6y) = 2 (6)
⇒ -16x - 12y = 12
By combining this new equation with the first one, we can eliminate x and solve for y :
(16x - 10y) + (-16x - 12y) = 10 + 12
⇒ -22y = 22
⇒ y = -1
Then we just solve for x by replacing y in either equation.
16x - 10y = 10
⇒ 16x - 10 (-1) = 10
⇒ 16x + 10 = 10
⇒ 16x = 0
⇒ x = 0
The main idea behind elimination is combining the given equations in just the right amount so that one of the variables disappears. The "right amount" involves using the LCM of the coefficients of a given variable. In this example, the x-coefficients had LCM(8, 16) = 16, so we only had to scale one of the equations (the one with -8x) to cancel all the x terms.
If we wanted to eliminate y first instead, we first note that LCM(6, 10) = 30. To get 30 as a coefficient on y, in the first equation we would have multiplied by 3:
16x - 10y = 10
⇒ 3 (16x - 10y) = 3 (10)
⇒ 48x - 30y = 30
And in the second equation, we would have multiplied by -5 (negative so that upon combining the equations, we end up with -30y + 30y = 0):
-8x - 6y = 6
⇒ -5 (-8x - 6y) = -5 (6)
⇒ 40x + 30y = -30
Now combining the two scaled equations gives
(48x - 30y) + (40x + 30y) = 30 + (-30)
⇒ 88x = 0
⇒ x = 0
We then solve for y :
16x - 10y = 10
⇒ -10y = 10
⇒ y = -1
so we end up with the same solution as before.
The price of an item has been reduced by 45%. The original price was $60. What is the price of the item now?
Answer:
the answer to the question is 15$
CD is a line parallel to AB and passes through the point (3, 5).
c. Find the equation of the line CD
Answer:
y=5/3x+b
Step-by-step explanation:
Supposing CD uses the equation y=mb (meaning CD passes through the origin) and passes through (3,5), we then know the slope if 5/3 and the y intercept is 0. We can then write CD's equation as y=5/3x+0, or just y=5/3x.
So if AB is parallel to CB, then their equation is y=5/3x+b, as we don't the y-intercept yet.
Thank you!
John is 9 times as heavy as his dog.
Determine which of the statement's below is true.
O John weighs 900% more than his dog.
O John weighs 800% more than his dog.
O John's dog weighs 800% less than John.
sources
O John weight is 800% of his dog's weight.
Answer:
John weighs 900% more than his dog
Step-by-step explanation:
The weight of John is 8x more than his dog.
Given that, John is 9 times as heavy as his dog.
What is percentage?Percentage is defined as a given part or amount in every hundred. It is a fraction with 100 as the denominator and is represented by the symbol "%".
Let weight of John's dog be x, then weight of John will be 9x.
Difference of weight = 9x-x
= 8x
Therefore, the weight of John is 8x more than his dog.
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find the zeros of each function. State the multiplicity of multiple zeros y=2x^3+x^2-x
Answer:
Step-by-step explanation:
To find the roots/zeros, set
2
x
3
+
x
2
−
x
equal to
0
and solve.
2
x
3
+
x
2
−
x
=
0
Factor the left side of the equation.
Tap for more steps...
x
(
2
x
−
1
)
(
x
+
1
)
=
0
If any individual factor on the left side of the equation is equal to
0
, the entire expression will be equal to
0
.
x
=
0
2
x
−
1
=
0
x
+
1
=
0
Set the first factor equal to
0
.
x
=
0
Set the next factor equal to
0
and solve.
Tap for more steps...
x
=
1
2
Set the next factor equal to
0
and solve.
Tap for more steps...
x
=
−
1
The final solution is all the values that make
x
(
2
x
−
1
)
(
x
+
1
)
=
0
true. The multiplicity of a root is the number of times the root appears.
x
=
0
(Multiplicity of
1
)
x
=
1
2
(Multiplicity of
1
)
x
=
−
1
(Multiplicity of
1
)
Answer:
-1, 0, 1/2
Step-by-step explanation:
The function can be factored as ...
y = x(2x^2 +x -1)
y = x(2x -1)(x +1)
The factors are unique, so each zero has multiplicity 1. The zeros are the values of x that make the factors zero:
-1, 0, 1/2 . . . . zeros of the function; each with multiplicity 1
Find the area of the triangle
[tex] =( \frac{1}{2} \times 10.4 \times 16.9) {ft}^{2} \\ = (5.2 \times 16.9) {ft}^{2} \\ = 87.88 {ft}^{2} [/tex]
Answer:
The area of the triangle is 87.88 square feet.
Hope you could get an idea from here.
Doubt clarification - use comment section.
what is:
k–66≤ – 84
in one-step inequalities?
Answer:
[tex]k\le \:-18[/tex]
Step-by-step explanation:
First, you add 66 to both sides so then the equation you are trying to solve will be: [tex]k-66+66\le \:-84+66[/tex]
Finally, you simplify and get: [tex]k\le \:-18[/tex]
Hope this helped!
explain or show that the point (5,-4) is a solution to this system of equations
Answer:
You could substitute the point (5,-4) into each equation
Step-by-step explanation:
x=5 y=-4
3x-2y=23
3(5)-2(-4)=23
15+8=23
23=23
2x+y=6
2(5)+(-4)=6
10-4=6
6=6
The points go into each equation which proves that the point (5,-4) is the solution.
(i don't know if I did this right, I apologize if I didn't
PLZ HELP ME!! IF YOUR A GENUIS
The equation 4.05p+14.40=4.50(p+3) represents the number of p of pounds of penuts you need to make a trail mix. How many pounds of peanuts do you need for the trail mix?
Since "p" represents the number of pounds of peanuts and:
4.05p + 14.40 = 4.50(p + 3) [then by distributing we have:
4.05p + 14.40 = 4.50p + 13.5 [then by subtracting 13.5 from both sides we have:
4.05p + 0.9 = 4.50p [then by subtracting 4.05p from both sides we have:
0.9 = 0.45p [then by dividing both sides by 0.45 we have:
2 = p
So there are 2 pounds of peanuts needed for the trail mix.
PLEASE HELP!
Determine the value of X.
Answer:
Generally, the algebraic expression should be any one of the forms such as addition, subtraction, multiplication and division. To find the value of x, bring the variable to the left side and bring all the remaining values to the right side. Simplify the values to find the result.
Step-by-step explanation:
Find the polynomial function in standard form that has the zeros listed. 1(multiplicity 2), -2(multiplicity 3)
Answer:
f(x) = x⁵ +4x⁴ +x³ -10x² -4x+8
Step-by-step explanation:
If p is a zero, then (x -p) is a factor. The multiplicity of the zero tells you how many times that is a factor (its exponent).
f(x) = (x -1)²(x +2)³ = (x² -2x +1)(x³ +6x² +12x +8)
f(x) = x⁵ +4x⁴ +x³ -10x² -4x+8
_____
Additional comment
You can use the distributive property to write out the 12 terms of the product of the two expanded factors, or you can do a little mental arithmetic based on what you know about the exponent of a product term. (It is the sum of the exponents of its factors.)
The mental exercise can be made easier by writing the coefficients of the factors as though they were two cubics. It works well to write them in two rows:
[tex]\left[\begin{array}{cccc}0&1&-2&1\\1&6&12&8\end{array}\right][/tex]
The columns are in order of decreasing powers of x. A relatively simple and symmetrical pattern of sums of cross products is used to find the coefficients of the final polynomial. Working in order of decreasing exponents, we have ...
coefficient of x^6 = (0)(1) = 0
coefficient of x^5 = (0)(6) +(1)(1) = 1
coefficient of x^4 = (0)(12) +(1)(-2) +(1)(6) = 4
coefficient of x^3 = (0)(8) +(1)(1) +(1)(12) +(6)(-2) = 1
coefficient of x^2 = (1)(8) +(6)(1) +(-2)(12) = -10
coefficient of x^1 = (-2)(8) +(12)(1) = -4
coefficient of x^0 = (1)(8) = 8
Elliott needs 3/4 of a cup of sugar to make a dozen chocolate chip cookies. How many cups of sugar does he
need to make 4 dozen.
Answer:
3 cups
Step-by-step explanation:
3/4 times 4 equals 12/4. divide and get 3.
An ice cream cup has 3 scoops of chocolate, 4 scoops of vanillas and 3 scoops of butter scotch ice cream. What is the probability that if you randomly sampled the ice cream that you will taste chocolate or vanilla ice cream?
Answer:
7 out of 10
Step-by-step explanation:
if you have 10 in the cup then you add
4 vanilla 3 chocolate = 7
and add all scoops together and you get 10
so your probability would be 7 out of 10
another way to say it is
the probability of getting chocolate or vanilla ice cream from the cup would be 7 out of 10
Which frequency table is consistent with the histogram of weights of 86 different students, below?
Answer:
B
Step-by-step explanation:
The incorrect tables each have at least one flaw that makes it not match the histogram.
A. The relative frequency associated with 4 of 86 is about 0.047, not 0.055. The relative frequencies are incorrect.
B. this table matches the histogram
C. The "bins" are not of uniform width, nor are they centered on the same values as shown in the histogram.
D. The values in a cumulative frequency table should be non-decreasing. The table value of 24 should be 54.
A store sells tents,sleeping bags,and campstools.A customer buys a tent, 2 sleeping bags, and 3 campstools for 212$.the price of the tent is 5 times the cost of a campstool.the cost of a sleeping bag is 6$more than the cost of a campstool.find the cost of was just item
The cost of each campstools, tent and sleeping bag is $20, $100 and $26
let
tent = 1
sleeping bags = 2
campstools = 3
Total cost = $212
tent = t
sleeping bags = s
campstools = c
If
t = 5c
s = c + 6
Total = t + 2s + 3c
212 = 5c + 2(c + 6) + 3c
212 = 5c + 2c + 12 + 3c
212 = 10c + 12
212 - 12 = 10c
200 = 10c
c = 200/10
c = 20
t = 5c
= 5 × 20
= 100
s = c + 6
= 20 + 6
= 26
Therefore, the cost of each campstools, tent and sleeping bag is $20, $100 and $26
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Triangle H J K is cut by line segment A B. Line segment A B goes from side H J to side H K. The length of H A is 5. 25 inches, the length of H B is 3 inches, and the length of B K is 5 inches. What is the length of Line segment A J if Line segment A B is parallel to lines segment J K? 8 in. 8. 75 in. 10. 25 in. 14 in.
The segments on triangle HJK are illustrations of equivalent ratios
The length of line AJ is 8.75 inches
The given parameters are:
[tex]H A = 5.25[/tex]
[tex]HB = 3[/tex]
[tex]BK = 5[/tex]
Because lines AB and JK are parallel lines, then we have the following equivalent ratios
[tex]HA:HB = AJ:BK[/tex]
Substitute values for length HA, HB and BK.
[tex]5.25:3 = AJ:5[/tex]
Express both ratios as fractions
[tex]\frac{5.25}{3} = \frac{AJ}5[/tex]
Multiply both sides by 5
[tex]\frac{5.25}{3} \times 5= AJ[/tex]
[tex]8.75= AJ[/tex]
Rewrite as:
[tex]AJ = 8.75[/tex]
Hence, the length of line AJ is 8.75 inches
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You have at most $10 to spend on notebooks and markers. Markers cost $1 each, and
notebooks cost $1.25 each. You want to buy at least 5 items. Write an inequality that
represents this situation. Identify and interpret two solutions.
I need help! please! Ill give brainiest
I don't agree with Cameron
The relation { (1,2), (1,3) } has the domain {1} and range {2,3}.
The domain describes the list of x coordinates of the relation, while the range is the set of y coordinates. While we don't have a function, this is a relation.
help please anybody Mhm
Answer:
B
Step-by-step explanation:
Answer:
Your answer would be C
Step-by-step explanation:
Because its a ratio of integers with a nonzero denominator.
Thanks so very much!!
Answer:
yw
Step-by-step explanation:
Solve for b
32 = 12 + 5/6b
Answer:
b=24, please give Brainliest if this helped you
Step-by-step explanation:
a movie rental service charges a $15 fee plus $1.50 per rental. suppose you have $40 to spend. how many movies can you rent
Answer:
16
Step-by-step explanation:
y = mx+b, where y is cost x is # of movies, m is $ per rental and b is the flat charge.
y = 1.50x+15
40 = 1.50x+15
25 = 1.50x
16.666... = x
You can rent about 16 movies
Hope that helps
Answer:
40 = 1.50x+15
25=1.50x
x=16
16 movies
Step-by-step explanation:
Anyone know how to solve 28?
Answer:
i need help too
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
x = - 3 is a vertical line parallel to the y- axis.
A line perpendicular to it will therefore be a horizontal line parallel to the x- axis with equation
y = c
where c is the value of the y- coordinates the line passes through.
The line passes through (6, - 4 ) with y- coordinate - 4 , then
y = - 4 ← equation of perpendicular line
The square of a number minus twice the number is 48. Find the number.
Answer: 8 or -6
Step-by-step explanation:
x^2 - 2x = 48
x^2 - 2x - 48 = 0
(x-8)(x+6) = 0
x = 8 or -6
HELP It's due in 15 minutes
Answer:
L
Step-by-step explanation:
Someone please help me with this
Find the area, in square inches, of a square with a side length 1/4 in.
Answer:1/16 squared
Step-by-step explanation:
1/4*1/4
4*4=16
1/16
1. Calculate the equation of the line through the points (1, 1), (4, 3), (10, 7) and (40, 27).
Answer:
y = (2/3)x + 1/3
Step-by-step explanation:
Check that a single straight line will actually go through all four of these points. Going from (1, 1) to (4, 3), the 'rise' is 2 and the 'run' is 3, which would make the slope, m, equal rise/run = 2/3. Going from (4,3) to (10, 7), m = rise/run = 4/6 = 2/3 (again).
Let's find the slope-intercept form of the equation of this line: y = mx + b
Arbitrarily choose the point (1, 1). Here x = 1, y = 1 and m = 2/3. Then
we have
1 = (2/3)(1) + b, or 1 = 2/3 + b, so that b must be 1/3.
The equation in question is y = (2/3)x + 1/3
What is this expression translated into words?
2n + 1
a
one plus 2 divided by a number n
b
2 times 1 added to a number n
c
two times a number n added to one
Answer:
C. two times a number n added to one
Need help please if anyone one can help me now I will like that. Thanks