Question

ПОМОГИТЕ ПОЖАЛУЙСТА!!!!!!!

Answer 1

$\displaystyle 15a^4-5a^3=5a^3(3a-1)\\\\6x-6y+ax-ay=6(x-y)+a(x-y)=(x-y)(6+a)\\\\x^2-49=x^2-7^2=(x-7)(x+7)$