If z-3 = 0, then z = 3 when we isolate z If z = 3, and z = 3^x, then z = 3 3^x = 3 3^x = 3^1 x = 1 which is a solutin in terms of x
If z+1 = 0 then z = -1 If z = -1 and z = 3^x, then there are NO solutions for this part of the equation The quantity 3^x is never negative no matter what the x value is