Question

Multiply (in horizontal and vertical arrangement):

(3) (p + 3) × (p − 3)

Answer 1

(p + 3) × (p − 3)
Horizontal arrangement:
= (p + 3) × p − (p + 3) × 3
= p × p + 3 × p − p × 3 − 3 × 3
= p² + 3p − 3p − 9
= p² − 9
Vertical arrangement:
$\begin{array}{c}\begin{array}{ccccc}& & p& +& 3\end{array}\\ \begin{array}{ccccc}& \times & p& -& 3\end{array}\\ \overline{\begin{array}{ccccc}& & -3p& -& 9\end{array}}\\ \begin{array}{ccccc}+p^2& +& 3p& & \end{array}\\ \underline{\overline{\begin{array}{ccccc}{p}^2& +& 0p& -& 9\end{array}}}\end{array}$