4 years ago

Subtitute 2x+y=7 and 3x-y=8

Mathematics

1 answer:

iogann1982 [59]4 years ago

8 0

Answer:

x = 3 , y = 1

Step-by-step explanation:

2x + y = 7

3x + y = 8

solution

2x + y = 7-----------(1)

3x - y = 8------------(2)

from equation 1

2x + y = 7

y = 7 - 2x-------------(3)

substitute equation 3 into equation 2

3x - y = 8

3x - (7 - 2x) = 8

3x - 7 + 2x = 8

3x + 2x = 8 + 7

5x = 15

divide through by the coefficient of x

5x/5 = 15/5

x = 3

to find y

substitute x into equation 1

2x + y = 7

2(3) + y = 7

6 + y = 7

y = 7 - 6

y = 1

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