Substituting

Given that x= 7 in the equation x+2y=21, find y.

Given that x= -2 in the equation 5x+4y=46, find y.

Given that x= $\frac{2}{3}$   in the equation 3x-y=2, find y.

Given that x= 5 in the equation -x+2y=11, find y.

Given that x= -3 in the equation -2x+7y=20, find y.

Given that y= 3 in the equation x+3y=21, find x.

Given that y= -2 in the equation 5x-3y=26, find x.

Given that y= $\frac{7}{5}$   in the equation 2x+10y=12, find x.

Given that  $y=-\frac{2}{5}$    in the equation 5x+15y=14, find x.

Given that y= -3.5 in the equation -2x-4y=4, find x.