Answer :
[tex]g5-h3=g*5-h*3= \\ \\ = 2*5-7*3= \\ \\ =10-21= \\ \\ = \boxed{-11}[/tex]
[tex]g^5-h^3\\\\g=2;\ h=7\\\\2^5-7^3=2\times2\times2\times2\times2-7\times7\times7=32-343=-311[/tex]