Question

Factorise the following:
2x² + 3x $-$ 5

Answer 1

$$\begin{gathered} 2x^2+3x-5 \\ =2x^2+5x-2x-5\left[\because 2\times \left(-5\right)=-10 \\ 5\times \left(-2\right)=-10 \\ \mathrm{and}5+\left(-2\right)=3\right] \\ =x\left(2x+5\right)-1\left(2x+5\right) \\ =\left(2x+5\right)\left(x-1\right) \end{gathered}$$