3x^2-9=x^2+4

Solution for 3x^2-9=x^2+4 equation:

Simplifying
3x2 + -9 = x2 + 4

Reorder the terms:
-9 + 3x2 = x2 + 4

Reorder the terms:
-9 + 3x2 = 4 + x2

Solving
-9 + 3x2 = 4 + x2

Solving for variable 'x'.

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

Add '-1x2' to each side of the equation.
-9 + 3x2 + -1x2 = 4 + x2 + -1x2

Combine like terms: 3x2 + -1x2 = 2x2
-9 + 2x2 = 4 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
-9 + 2x2 = 4 + 0
-9 + 2x2 = 4

Add '9' to each side of the equation.
-9 + 9 + 2x2 = 4 + 9

Combine like terms: -9 + 9 = 0
0 + 2x2 = 4 + 9
2x2 = 4 + 9

Combine like terms: 4 + 9 = 13
2x2 = 13

Divide each side by '2'.
x2 = 6.5

Simplifying
x2 = 6.5

Take the square root of each side:
x = {-2.549509757, 2.549509757}