Andrew M. answered • 04/19/15
Tutor
New to Wyzant
Mathematics - Algebra a Specialty / F.I.T. Grad - B.S. w/Honors
Note: (sqrt(x))2=x
Example: (sqrt(4))2= 22=4
Also: If the sqrt(x) = y then x = y2
Example: sqrt(9) = 3 so 9 = 32
In the problem given we have sqrt(2x2-144) = 144
Squaring both sides we get
2x2-144 = 1442
2x2= 20736 + 144
2x2= 20880
x2 = 20880/2
x2 = 10440
x = +-sqrt(10440) = 102.176 or -102.176
