3(x^2+6)=90

Solution for 3(x^2+6)=90 equation:

Simplifying
3(x2 + 6) = 90

Reorder the terms:
3(6 + x2) = 90
(6 * 3 + x2 * 3) = 90
(18 + 3x2) = 90

Solving
18 + 3x2 = 90

Solving for variable 'x'.

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

Add '-18' to each side of the equation.
18 + -18 + 3x2 = 90 + -18

Combine like terms: 18 + -18 = 0
0 + 3x2 = 90 + -18
3x2 = 90 + -18

Combine like terms: 90 + -18 = 72
3x2 = 72

Divide each side by '3'.
x2 = 24

Simplifying
x2 = 24

Take the square root of each side:
x = {-4.898979486, 4.898979486}