Simultaneous equation: (x-3y)=9,(2x+3y)=0

Using one of the equations we express either x in the form of y, or y in the form of x. We then put this expression of x/y into the other equation. This allows us to calculate the numerical values of both x and y.1) x=9+3y, 2)(2(9+3y)+3y)=0, 3)y=-2, 4)x=9+3(-2), 5)x=3