Question

x − 7y = 20
x + 12y = −1

Find the value for x

Answer 1

-19y=21
=> y=-21/19
Now you can solve x

Answer 2

subtract columns

0x - 19y = 21

or

-19y = 21 which means y = 21/-19

substitute into x + 12y = −1

x + 12(21/-19) = −1

or

x - 252/21 = -1

add 252/21 to both sides therefore,

x = 231/21