Chapter 4.7, Problem 12GP

To determine

Solve each equation and round to the nearest tenth , if necessary.

Answer to Problem 12GP

The solution of equation $4r^3=32$ is $r=2$ .

Explanation of Solution

Given information:

The equation is $4r^3=32$ .

Calculation:

The equation is $4r^3=32$ .

  $\begin{array}{l}4r^3=32\\ r^3=8\\ r^3-8=0\\ r^3-{\left(2\right)}^3=0\\ \left(r-2\right)\left(r^2+2r+4\right)=0\end{array}$

Since $r^2+2r+4\ne 0$

Therefore,

  $\begin{array}{l}r-2=0\\ r=2\end{array}$

Therefore , the solution of equation $4r^3=32$ is $r=2$ .