we are given
[tex] 5r^2-12=68 [/tex]
Since, we have to solve for r
so, firstly we will isolate r terms
so, we will move 12 on right side
we can add both sides by 12
[tex] 5r^2-12+12=68+12 [/tex]
[tex] 5r^2=80 [/tex]
now, we can divide both sides by 5
[tex] \frac{5r^2}{5} =\frac{80}{5} [/tex]
[tex] r^2=16 [/tex]
now, we can take sqrt both sides
and we get
[tex] r=4 , r=-4 [/tex]
so,
{±4}..........Answer
