Chapter 4.2, Problem 31E

To determine

To solve: The equation $4r^2-r=5$

Answer to Problem 31E

  $r=\frac{5}{4}\text{ or }r=-1$

Explanation of Solution

Given information: $4r^2-r=5$

Calculation:

Given

  $4r^2-r-5=0$

That is: $\left(4r-5\right)\left(r+1\right)=0,$

Thus: $4r-5=0\text{ or }r+1=0$

That is:

  $r=\frac{5}{4}\text{ or }r=-1$