Question

Simplify

(3x + 4)(2x − 3) + (5x − 4)(x + 2)

Answer 1

(3x +4)(2x -3)
$$\begin{gathered} =3\mathrm{x}\times (2\mathrm{x}-3)+4\times (2\mathrm{x}-3) \\ =6{\mathrm{x}}^{(1+1)}-9\mathrm{x}+8\mathrm{x}-12 \\ =6{\mathrm{x}}^2-\mathrm{x}-12 \\ (5\mathrm{x}-4)(\mathrm{x}+2) \\ =5\mathrm{x}(\mathrm{x}+2)-4(\mathrm{x}+2) \\ =5{\mathrm{x}}^{(1+1)}+10\mathrm{x}-4\mathrm{x}-8 \\ =5{\mathrm{x}}^2+6\mathrm{x}-8 \end{gathered}$$

∴ (3x + 4)(2x − 3) + (5x − 4)(x + 2)

$$\begin{gathered} =6x^2-x-12+5x^2+6x-8 \\ =11x^2+5x-20 \end{gathered}$$