2x^2-9-18=0

Solution for 2x^2-9-18=0 equation:

Simplifying
2x2 + -9 + -18 = 0

Reorder the terms:
-9 + -18 + 2x2 = 0

Combine like terms: -9 + -18 = -27
-27 + 2x2 = 0

Solving
-27 + 2x2 = 0

Solving for variable 'x'.

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

Add '27' to each side of the equation.
-27 + 27 + 2x2 = 0 + 27

Combine like terms: -27 + 27 = 0
0 + 2x2 = 0 + 27
2x2 = 0 + 27

Combine like terms: 0 + 27 = 27
2x2 = 27

Divide each side by '2'.
x2 = 13.5

Simplifying
x2 = 13.5

Take the square root of each side:
x = {-3.674234614, 3.674234614}