Question

Factor using ac-method and factor completely, 25x²-30x--40  (help)

Answer 1

$25x^2-30x-40=\\ 5(5x^2-6x-8)=\\ 5(5x^2-10x+4x-8)=\\ 5(5x(x-2)+4(x-2))=\\ 5(5x+4)(x-2)$

Answer 2

Answer :$25x^2-30x-40 \\ =5(5x^2-10x+4x-8) \\ =5[5x(x-2)+4(x-2)] \\ =5(x-2)(5x+4)$