10=x*(x+3x)

Solution for 10=x*(x+3x) equation:

Simplifying
10 = x(x + 3x)

Combine like terms: x + 3x = 4x
10 = x(4x)

Remove parenthesis around (4x)
10 = x * 4x

Reorder the terms for easier multiplication:
10 = 4x * x

Multiply x * x
10 = 4x2

Solving
10 = 4x2

Solving for variable 'x'.

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

Add '-4x2' to each side of the equation.
10 + -4x2 = 4x2 + -4x2

Combine like terms: 4x2 + -4x2 = 0
10 + -4x2 = 0

Add '-10' to each side of the equation.
10 + -10 + -4x2 = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -4x2 = 0 + -10
-4x2 = 0 + -10

Combine like terms: 0 + -10 = -10
-4x2 = -10

Divide each side by '-4'.
x2 = 2.5

Simplifying
x2 = 2.5

Take the square root of each side:
x = {-1.58113883, 1.58113883}