Chapter 8.4, Problem 33PPS

To determine

To find: The product ${\left(3q-5r\right)}^2$

Answer to Problem 33PPS

  $9q^2-30qr+25r^2$

Explanation of Solution

Given:

  ${\left(3q-5r\right)}^2$

Calculation:

The given expression is ${\left(3q-5r\right)}^2$

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

  $\begin{array}{l}{\left(3q-5r\right)}^2\\ ={\left(3q\right)}^2-2\cdot 3q\cdot 5r+{\left(5r\right)}^2\\ =9q^2-30qr+25r^2\end{array}$