Question

Check whether the following is solution of the equation $x-2y=4$ or not: $(1,1)$

Answer 1

If $(1,1)$ is solution of equation $x-2y=4$, then it must satisfy the equation.

Therefore,

$1-2\times 1=-1\ne 4$

Hence $(1,1)$ is not a solution of equation $x-2y=4$.