4x^2+8x^2-140=0

Solution for 4x^2+8x^2-140=0 equation:

Simplifying
4x2 + 8x2 + -140 = 0

Reorder the terms:
-140 + 4x2 + 8x2 = 0

Combine like terms: 4x2 + 8x2 = 12x2
-140 + 12x2 = 0

Solving
-140 + 12x2 = 0

Solving for variable 'x'.

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

Add '140' to each side of the equation.
-140 + 140 + 12x2 = 0 + 140

Combine like terms: -140 + 140 = 0
0 + 12x2 = 0 + 140
12x2 = 0 + 140

Combine like terms: 0 + 140 = 140
12x2 = 140

Divide each side by '12'.
x2 = 11.66666667

Simplifying
x2 = 11.66666667

Take the square root of each side:
x = {-3.415650256, 3.415650256}