(2+7c)(2-7c)=

Solution for (2+7c)(2-7c)= equation:

Simplifying
(2 + 7c)(2 + -7c) = 0

Multiply (2 + 7c) * (2 + -7c)
(2(2 + -7c) + 7c * (2 + -7c)) = 0
((2 * 2 + -7c * 2) + 7c * (2 + -7c)) = 0
((4 + -14c) + 7c * (2 + -7c)) = 0
(4 + -14c + (2 * 7c + -7c * 7c)) = 0
(4 + -14c + (14c + -49c2)) = 0

Combine like terms: -14c + 14c = 0
(4 + 0 + -49c2) = 0
(4 + -49c2) = 0

Solving
4 + -49c2 = 0

Solving for variable 'c'.

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

Add '-4' to each side of the equation.
4 + -4 + -49c2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -49c2 = 0 + -4
-49c2 = 0 + -4

Combine like terms: 0 + -4 = -4
-49c2 = -4

Divide each side by '-49'.
c2 = 0.08163265306

Simplifying
c2 = 0.08163265306

Take the square root of each side:
c = {-0.285714286, 0.285714286}