Solve 2v^2-90=0, where v is a real number

First thing you want to do is put v by itself

Add 90 to both sides

2v^2 = 90

Divide by 2 on both sides

v^2 = 45

And then take the sqrt (45)

v = sqrt (45)

We can reduce this by finding the perfect square which is 9

v = sqrt (9) * sqrt (5)

So,

v = 3 * sqrt (5)