7=(3.5x)(3.5x)

Solution for 7=(3.5x)(3.5x) equation:

Simplifying
7 = (3.5x)(3.5x)

Remove parenthesis around (3.5x)
7 = 3.5x(3.5x)

Remove parenthesis around (3.5x)
7 = 3.5x * 3.5x

Reorder the terms for easier multiplication:
7 = 3.5 * 3.5x * x

Multiply 3.5 * 3.5
7 = 12.25x * x

Multiply x * x
7 = 12.25x2

Solving
7 = 12.25x2

Solving for variable 'x'.

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

Add '-12.25x2' to each side of the equation.
7 + -12.25x2 = 12.25x2 + -12.25x2

Combine like terms: 12.25x2 + -12.25x2 = 0.00
7 + -12.25x2 = 0.00

Add '-7' to each side of the equation.
7 + -7 + -12.25x2 = 0.00 + -7

Combine like terms: 7 + -7 = 0
0 + -12.25x2 = 0.00 + -7
-12.25x2 = 0.00 + -7

Combine like terms: 0.00 + -7 = -7
-12.25x2 = -7

Divide each side by '-12.25'.
x2 = 0.5714285714

Simplifying
x2 = 0.5714285714

Take the square root of each side:
x = {-0.755928946, 0.755928946}