Chapter 8.4, Problem 4BGP

To determine

To find: The product $\left(4c-7d\right)\left(4c+7d\right)$

Answer to Problem 4BGP

  $16c^2-49d^2$

Explanation of Solution

Given:

  $\left(4c-7d\right)\left(4c+7d\right)$

Calculation:

The given expression is $\left(4c-7d\right)\left(4c+7d\right)$

Apply the formula $\left(a+b\right)\left(a-b\right)=a^2-b^2$ and then simplify

  $\begin{array}{l}\left(4c-7d\right)\left(4c+7d\right)\\ ={\left(4c\right)}^2-{\left(7d\right)}^2\\ =16c^2-49d^2\end{array}$