(4x+20)*(4x-20)=35

Solution for (4x+20)*(4x-20)=35 equation:

Simplifying
(4x + 20)(4x + -20) = 35

Reorder the terms:
(20 + 4x)(4x + -20) = 35

Reorder the terms:
(20 + 4x)(-20 + 4x) = 35

Multiply (20 + 4x) * (-20 + 4x)
(20(-20 + 4x) + 4x * (-20 + 4x)) = 35
((-20 * 20 + 4x * 20) + 4x * (-20 + 4x)) = 35
((-400 + 80x) + 4x * (-20 + 4x)) = 35
(-400 + 80x + (-20 * 4x + 4x * 4x)) = 35
(-400 + 80x + (-80x + 16x2)) = 35

Combine like terms: 80x + -80x = 0
(-400 + 0 + 16x2) = 35
(-400 + 16x2) = 35

Solving
-400 + 16x2 = 35

Solving for variable 'x'.

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

Add '400' to each side of the equation.
-400 + 400 + 16x2 = 35 + 400

Combine like terms: -400 + 400 = 0
0 + 16x2 = 35 + 400
16x2 = 35 + 400

Combine like terms: 35 + 400 = 435
16x2 = 435

Divide each side by '16'.
x2 = 27.1875

Simplifying
x2 = 27.1875

Take the square root of each side:
x = {-5.214163404, 5.214163404}