Question

Whether (2,2) is a solution to the equations 3x−y=4 and 2x+y=1?

Answer 1

$3x - y = 4 \\ 2x + y = 1 \\ ans) 3x - y = 4 \times 2 \\ \: \: \: \: \: \: \: \: \: 2x + y = 1 \times 3 \\ 6x - 2y = 8 \\ 6x + 3y = 3 \\ ( - ) (- ) = ( - ) \\ - 5y = 5 \\ \: \: \: \: \: y = - 1 \\ \\ 6x - 2y = 8 \\ 6x - 2( - 1) = 8 \\ 6x + 2 = 8 \\ \: \: \: \: \: \: \: \: \: 6x = 8 - 2 \\ \: \: \: \: \: \: \: \: \: 6x = 6 \\ \: \: \: \: \: \: \: \: \: \: \: \: x = 1$

Therefore (2,2) are not the solution to this equation.