8x^2-4x^2-9=0

Solution for 8x^2-4x^2-9=0 equation:

Simplifying
8x2 + -4x2 + -9 = 0

Reorder the terms:
-9 + 8x2 + -4x2 = 0

Combine like terms: 8x2 + -4x2 = 4x2
-9 + 4x2 = 0

Solving
-9 + 4x2 = 0

Solving for variable 'x'.

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

Add '9' to each side of the equation.
-9 + 9 + 4x2 = 0 + 9

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

Combine like terms: 0 + 9 = 9
4x2 = 9

Divide each side by '4'.
x2 = 2.25

Simplifying
x2 = 2.25

Take the square root of each side:
x = {-1.5, 1.5}