Question

(6-c)^2
(c-4)(c+4)
-(6-5c)(5c+6)

Answer 1

$(6-c)^2=36-12c+c^2 \ (c-4)(c+4)=c^2-4^2=c^2-16 \ -(6-5c)(5c+6)=(5c-6)(5c+6)=25c^2-36$