4x^2-15=123

Solution for 4x^2-15=123 equation:

Simplifying
4x2 + -15 = 123

Reorder the terms:
-15 + 4x2 = 123

Solving
-15 + 4x2 = 123

Solving for variable 'x'.

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

Add '15' to each side of the equation.
-15 + 15 + 4x2 = 123 + 15

Combine like terms: -15 + 15 = 0
0 + 4x2 = 123 + 15
4x2 = 123 + 15

Combine like terms: 123 + 15 = 138
4x2 = 138

Divide each side by '4'.
x2 = 34.5

Simplifying
x2 = 34.5

Take the square root of each side:
x = {-5.873670062, 5.873670062}