Question

Multiply $\left(x+3\right)\left(x-7\right)$.

Answer 1

Multiplying a polynomial by a polynomial.

We know that, “To multiply one binomial by another binomial, multiply each individual term in one binomial by each individual term in the other binomial using the distributive property of multiplication.”

$\begin{array}{rcl}\left(x+3\right)\left(x-7\right)& =& x\left(x-7\right)+3\left(x-7\right)\\ & =& x^2-7x+3x-21\\ & =& x^2-4x-21\end{array}$

Hence, $\left(x+3\right)\left(x-7\right)=x^2-4x-21$.