Chapter 8.4, Problem 6CYU

To determine

To find: The product ${\left(3c+6d\right)}^2$

Answer to Problem 6CYU

  $9c^2+36cd+36d^2$

Explanation of Solution

Given:

  ${\left(3c+6d\right)}^2$

Calculation:

The given expression is ${\left(3c+6d\right)}^2$

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

  $\begin{array}{l}{\left(3c+6d\right)}^2\\ ={\left(3c\right)}^2+2\cdot 3c\cdot 6d+{\left(6d\right)}^2\\ =9c^2+36cd+36d^2\end{array}$