Quick answer in 5 minutes` x@-3x-4 = (x-4)(x+1) The above factor is determined by x@-3x-4 How to evolve into (x-4) (x + 1) and what formula to use in it`` …… [@ for square]

Quick answer in 5 minutes` x@-3x-4 = (x-4)(x+1) The above factor is determined by x@-3x-4 How to evolve into (x-4) (x + 1) and what formula to use in it`` …… [@ for square]

Cross multiplication
x^2-3x-4 = (x-4)(x+1)