Question

Solve the simultaneous equations
-x + 4y = 12
x + y = - 7

Answer 1

y = 1, x = - 8 or (-8,1)

Explanation:

......

Answer 2

y = 1, x = - 8

or

(-8, 1)

Explanation:

-x + 4y = 12

x + y = -7

add the equations together

0x + 5y = 5

5y = 5

y = 1

substitute y for 1 in one of the original equations to find x

x + y = -7

x + 1 = -7

x + 1 - 1 = - 7 - 1

x = - 7 - 1

x = -8