Question

Factor the trinomial 5x^2-x-4

Answer 1

I think it’s (5x+4)(x-1)

Answer 2

(5x+4)(x-1)

Explanation:

`5x^2-x-4\\\\\mathrm{Break\:the\:expression\:into\:groups}\\=\left(5x^2+4x\right)+\left(-5x-4\right)\\\\\mathrm{Factor\:out\:}x\mathrm{\:from\:}5x^2+4x\mathrm{:\quad }x\left(5x+4\right)\\\mathrm{Factor\:out\:}-1\mathrm{\:from\:}-5x-4\mathrm{:\quad }-\left(5x+4\right)\\\\=x\left(5x+4\right)-\left(5x+4\right)\\\\\mathrm{Factor\:out\:common\:term\:}5x+4\\=\left(5x+4\right)\left(x-1\right)`