From the proportion, the product of extreme terms is equal to the product of interior terms
(48x^2)*(36x^2) = (64x^4)*x
Cancel common factors (16x^4) in both sides to get
3*36 = 4x
Cancel common factor 4 in both side to get
x = 3*9 = 27. ANSWER
ANSWER. x = 27.
Solved.