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Ann [662]
3 years ago
11

Solve each system by substitution.

Mathematics
1 answer:
jek_recluse [69]3 years ago
4 0
-8x + 4y = 20
-8x = 20 - 4y

Subtitute -8x with 20-4y
-8x + 7y = 5
(20-4y) + 7y = 5
20 + 3y = 5
3y = 5 - 20
3y = -15
y = -15/3
y = -5

Find x
-8x = 20 - 4y
-8x = 20 - 4(-5)
-8x = 20 + 20
-8x = 40
x = 40/-8
x = -5
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dezoksy [38]
The answer would be B.
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4 0
3 years ago
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John has decided to prepare an old field for his son's new horse. the length of the field is 10 meters less than 4 times its wid
tatuchka [14]

Answer: The total money invested in the field will be $1,623.80

Step-by-step explanation:

step 1

Find the dimensions of the field

Let

x -----> the length of the field

y -----> the width of the field

p=2(x+y)

p(4.80)=1,584

p=330m

we know that

The perimeter of the field is equal to

so

330=2(x+y)----> equation A

x=4y-10 ------> equation B

substitute equation B in equation A and solve for y

330=2(4y-10+y)

165=(5y-10)

5y=165+10

y+35

Find the value of x

x=4(35)-10+130

therefore

The length of the field is 130 meters and the width of the field is 35 meters

step 2

Find the area of the field

The area of the field is

A=xy

substitute

A=(130)(35)=4,550m2

step 3

Find the number of bags of seed

Divide the area by 460

4,550/460=9.89 bags

Round up to the nearest whole number

9.89 bags=10 bags

step 4

Find the cost of the seed

(10 )(3.98)=$19.8

step 5

Find the total money invested in the field

1,584+$39.8=$1,623.80

7 0
2 years ago
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Which postulate proves that the triangles below are similar?
Molodets [167]

Answer:

AA~

Step-by-step explanation:

These triangles are similar but not congruent. One triangle is bigger than the other, meaning none of the side lengths are the same. On the triangles, two angles are given, a 53 degree and a 90 meaning that you would us the AA rule to determine if they are similar. Which they are.

3 0
3 years ago
Solve the equation 5x+2-x=-4x
AVprozaik [17]
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hope this helps
8 0
3 years ago
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HELP ME WITH 16 & 17
damaskus [11]

__Data__

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Also if AB = AD = BD = CD that would mean all those sides have the exact same length

Answers and Explanations

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7 0
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