9x^2-400=0

Solution for 9x^2-400=0 equation:

Simplifying
9x2 + -400 = 0

Reorder the terms:
-400 + 9x2 = 0

Solving
-400 + 9x2 = 0

Solving for variable 'x'.

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

Add '400' to each side of the equation.
-400 + 400 + 9x2 = 0 + 400

Combine like terms: -400 + 400 = 0
0 + 9x2 = 0 + 400
9x2 = 0 + 400

Combine like terms: 0 + 400 = 400
9x2 = 400

Divide each side by '9'.
x2 = 44.44444444

Simplifying
x2 = 44.44444444

Take the square root of each side:
x = {-6.666666666, 6.666666666}