100=(4x)(x)

Solution for 100=(4x)(x) equation:

Simplifying
100 = (4x)(x)

Remove parenthesis around (4x)
100 = 4x(x)

Multiply x * x
100 = 4x2

Solving
100 = 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.
100 + -4x2 = 4x2 + -4x2

Combine like terms: 4x2 + -4x2 = 0
100 + -4x2 = 0

Add '-100' to each side of the equation.
100 + -100 + -4x2 = 0 + -100

Combine like terms: 100 + -100 = 0
0 + -4x2 = 0 + -100
-4x2 = 0 + -100

Combine like terms: 0 + -100 = -100
-4x2 = -100

Divide each side by '-4'.
x2 = 25

Simplifying
x2 = 25

Take the square root of each side:
x = {-5, 5}