4x^2+9x^2-225=0

Solution for 4x^2+9x^2-225=0 equation:

Simplifying
4x2 + 9x2 + -225 = 0

Reorder the terms:
-225 + 4x2 + 9x2 = 0

Combine like terms: 4x2 + 9x2 = 13x2
-225 + 13x2 = 0

Solving
-225 + 13x2 = 0

Solving for variable 'x'.

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

Add '225' to each side of the equation.
-225 + 225 + 13x2 = 0 + 225

Combine like terms: -225 + 225 = 0
0 + 13x2 = 0 + 225
13x2 = 0 + 225

Combine like terms: 0 + 225 = 225
13x2 = 225

Divide each side by '13'.
x2 = 17.30769231

Simplifying
x2 = 17.30769231

Take the square root of each side:
x = {-4.160251472, 4.160251472}