Question

Multiply:
(7x + y) by (x + 5y)

Answer 1

To multiply, we will use distributive law as follows:

$$\begin{gathered} \left(7x+y\right)\left(x+5y\right) \\ =7x\left(x+5y\right)+y\left(x+5y\right) \\ =7x^2+35xy+xy+5y^2 \\ =7x^2+36xy+5y^2 \end{gathered}$$

Thus, the answer is $7x^2+36xy+5y^2$.