Question

Find the product:

(7x + 2y)(x + 4y)

Answer 1

$$\begin{gathered} (7\mathrm{x}+2\mathrm{y})(\mathrm{x}+4\mathrm{y}) \\ =7\mathrm{x}\times (\mathrm{x}+4\mathrm{y})+2\mathrm{y}\times (\mathrm{x}+4\mathrm{y}) \\ =(7\mathrm{x}\times \mathrm{x}+7\mathrm{x}\times 4\mathrm{y})+(2\mathrm{y}\times \mathrm{x}+2\mathrm{y}\times 4\mathrm{y}) \\ =7{\mathrm{x}}^2+28\mathrm{xy}+2\mathrm{xy}+8{\mathrm{y}}^2 \\ =7{\mathrm{x}}^2+30\mathrm{xy}+8{\mathrm{y}}^2 \end{gathered}$$