90x^2-640=0

Solution for 90x^2-640=0 equation:

Simplifying
90x2 + -640 = 0

Reorder the terms:
-640 + 90x2 = 0

Solving
-640 + 90x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '640' to each side of the equation.
-640 + 640 + 90x2 = 0 + 640

Combine like terms: -640 + 640 = 0
0 + 90x2 = 0 + 640
90x2 = 0 + 640

Combine like terms: 0 + 640 = 640
90x2 = 640

Divide each side by '90'.
x2 = 7.111111111

Simplifying
x2 = 7.111111111

Take the square root of each side:
x = {-2.666666667, 2.666666667}