;-

Substitute for x and y

LHS

- 4 - 3 = - 7

RHS

7

Thus (-2,3) is not a solution

(-2, 3) isn't a solution of 2x - y = 7.

2(-2) - 3 = 7

-4 - 3 = 7

-7 = 7 which is false

so (-2, 3) is not a solution of 2x - y = 7

Check if it works in the equation:

Is this correct: 2(-2) - 3 = 7?

Is -7 =  7? No => "false"

no , - 7 ╪ 7...............................