(c-4)* (c+4)-(c+3)^2
5a^2*(-3a^3)^2

(c -4)(c +4) -(c +3)² =c² -16 -(c² +6c +9) =c² -16 -c² -6c -9 = -25 -6c5a²(-3a^3)² =5a² *9a^6 =45a^8