How do you solve #4r^2+1=325#?

1 Answer
Jan 20, 2017

Answer:

#r^2 = 81# which means #r# is either 9 or -9.

Explanation:

Given the equation #4r^2+1=325#, we are going to look for #r^2#

So to find #r^2# we are going to isolate it on one side of the equation.

Step 1:

Subtract 1 from both sides of the equation

#4r^2+1 -1 = 325-1#

So we get #4r^2 = 324#

Step 2:

Divide both sides by 4

#4r^2/4 = 324/4#

So now we isolated have #r^2# isolated

#r^2 = 81#

#r=+-9#