The graphs Ax + By: 18 and Ax - By: 6 intersect in (3,-2). He finds A and B.please I thank you much...:)

substitute your point (3,-2) on both equations:A(3)+b(-2)=18 <--equation 1a(3)-b(-2)=6 <--equation 2add both equations, you'll get6A=24A=4substitute the value of A in any equtionsequation 1: (4)(3)-2b=18simplify and solve for b, you'll get b=-3thus, A=4 & B=-3