Question

x^2-x-72

Answer 1

\(x^2-x-72\\ =x^2+8x-9x-72\\ =\left(x^2+8x\right)-\left(9x+72\right)\\ =x\left(x+8\right)-9\left(x+8\right)\\ =\left(x+8\right)\left(x-9\right)\)

Answer 2

`x^2 - x - 72`

`=x^2 - 2x.1/2 + 1/4 - 289/4`

`=(x - 1/2)^2 - (17/2)^2`

`=(x-1/2 - 17/2)(x-1/2 + 17/2)`

`= (x-9)(x+8)`