Solve this system of of equation using substitution x+2y=8

2x+y=7

1x + 2y = 8 ⇒ 1x + 2y = 8

2x + 1y = 7 ⇒ 4x + 2y = 14

-3x = - 6

-3 - 3

x = 2

x + 2y = 8

2 + 2y = 8

- 2 - 2

2y = 6

2 2

y = 3

(x, y) = (2, 3)

X+2y=8

2x+y=7

Solve for x in first eq: x=8-2y

Plug into second eq: 2 (8-2y) + y=7

Multiply out: 16-4y+y=7

Simplify: 16-3y=7

-3y = 7-16

-3y = - 9

y = 3 (diving two negatives makes positive)

Plug into our eq:

x=8-2 (3)

x = 2

So our answer: x=2, y=3

Verifying:

x+2y=8

2+2 (3) = 8?

2+6=8? True

2x+y=7

2 (2) + 3=7?

4+3=7? True

Answers verified.