x*x+2.4*x*2.4*x=55

Solution for x*x+2.4*x*2.4*x=55 equation:

Simplifying
x * x + 2.4x * 2.4x = 55

Multiply x * x
x2 + 2.4x * 2.4x = 55

Reorder the terms for easier multiplication:
x2 + 2.4 * 2.4x * x = 55

Multiply 2.4 * 2.4
x2 + 5.76x * x = 55

Multiply x * x
x2 + 5.76x2 = 55

Combine like terms: x2 + 5.76x2 = 6.76x2
6.76x2 = 55

Solving
6.76x2 = 55

Solving for variable 'x'.

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

Divide each side by '6.76'.
x2 = 8.136094675

Simplifying
x2 = 8.136094675

Take the square root of each side:
x = {-2.852384034, 2.852384034}