50=.5(x)(4x)

Solution for 50=.5(x)(4x) equation:

Simplifying
50 = 0.5(x)(4x)

Remove parenthesis around (4x)
50 = 0.5x * 4x

Reorder the terms for easier multiplication:
50 = 0.5 * 4x * x

Multiply 0.5 * 4
50 = 2x * x

Multiply x * x
50 = 2x2

Solving
50 = 2x2

Solving for variable 'x'.

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

Add '-2x2' to each side of the equation.
50 + -2x2 = 2x2 + -2x2

Combine like terms: 2x2 + -2x2 = 0
50 + -2x2 = 0

Add '-50' to each side of the equation.
50 + -50 + -2x2 = 0 + -50

Combine like terms: 50 + -50 = 0
0 + -2x2 = 0 + -50
-2x2 = 0 + -50

Combine like terms: 0 + -50 = -50
-2x2 = -50

Divide each side by '-2'.
x2 = 25

Simplifying
x2 = 25

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