Question

А) (х-4)²-25х² Б) а²-в²-4в-4а

Answer 1

(x-4)²-25x²=(x-4-5x)(x-4+5x)=(-4-4x)(6x-4)=-4(1+x)(6x-4)
a²-b²-4b-4a=(a-b)(a+b)-4(b+a)=(a+b)(a-b-4)