Question

I need help on 12 and 14 plzz and thank you

Answer 1

1)
3x^-1y^2x^3y^-1
when base are same powers add
3x^(-1+3)y^(-1+2)
3x^2y

2)
(-3) -(2)(-4)/(-2)-(-1)
(-3)+8/-2+1
-3+8/-1
5/-1
-5