Solve the system by substitution?

Question

2x + 5y = 13
y = –2x + 17

Answer 1

2x + 5y = 13- - - - - - Equation 1
y = - 2x + 17- - - - - - Equation 2
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substitute equation 2 into equation 1

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2x + 5y = 13

2x + 5(- 2x + 17) = 13

2x + (- 10x + 85) = 13

2x - 10x + 85 = 13

- 8x + 85 = 13

- 8x + 85 - 85 = 13 - 85

- 8x = - 72

- 8x / - 8 = - 72 / - 8

x = - 72 / - 8

x = 9

insert the x value into equation 2

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y = - 2x + 17

y = - 2(9) + 17

y = - 18 + 17

y = - 1

Insert the y value into equation 2

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Check for equaton 2

y = - 2x + 17

- 1 = - 2(9) + 17

- 1 = - 18 + 17

- 1 = - 1

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Check for equation 1

2x + 5y = 13

2(9) + 5(-1) = 13

18 + (- 5) = 13

18 - 5 = 13

13 = 13

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Both equations balance

The solution set { 9, - 1 }

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Answer 2

2x + 5 y = 13 (eq. 1)
y = - 2x + 17 (eq. 2)

Substitute eq. 2 to eq. 1

2x + 5 (-2x + 17) = 13
2x - 10x + 85 = 13
2x - 10x + 85 + 10 - 85 = 13 - 85
-8x = -72
-8x/-8 = -72/-8
x = 9 ==> the value of x, Substitute this value to eq. 2

y = - 2(9) + 17
y = -18 + 17
y = -1 ==> the value of y

To check:

2(9) + 5(-1) = 13
18 - 5 = 13
13 = 13

Answer 3

2x + 5y = 13
y = –2x + 17
2x + 5( –2x + 17) = 13
2x-10x+85 = 13
72 = 8x
x = 9
if x = 9, then y = –2(9) + 17
= -1

Answer 4

2x + 5.(-2x + 17) = 13
- 8x + 85 = 13
8x = 72
x = 9
y = - 18 + 17 = - 1
x = 9 , y = - 1

Answer 5

2x+5(-2x+17)=13
2x-10x+85=13
-8x=13-85
8x=72
x=9

substitute:
y=-2(9)+17
y=-18+17
y=-1

therefore x=9 and y=-1

Answer 6

2x + 5y = 13.............(a)
y = –2x + 17.............(b)

from (b)
subst -2x+17 for y in (a)

2x + 5(-2x+17) =13.......(c)
expand c

2x - 10x +85 =13
-8x = - 72
x=9........(d)
subt 9 for x in (b)

y= -2(9) +17
y = -18 +17
y= -1

Answer 7

why don't you people do your homework yourself rather than asking us?
i have to tell your parents to disconnect net connection!!!