(10-7a)(10+7a)=0

Solution for (10-7a)(10+7a)=0 equation:

Simplifying
(10 + -7a)(10 + 7a) = 0

Multiply (10 + -7a) * (10 + 7a)
(10(10 + 7a) + -7a * (10 + 7a)) = 0
((10 * 10 + 7a * 10) + -7a * (10 + 7a)) = 0
((100 + 70a) + -7a * (10 + 7a)) = 0
(100 + 70a + (10 * -7a + 7a * -7a)) = 0
(100 + 70a + (-70a + -49a2)) = 0

Combine like terms: 70a + -70a = 0
(100 + 0 + -49a2) = 0
(100 + -49a2) = 0

Solving
100 + -49a2 = 0

Solving for variable 'a'.

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

Add '-100' to each side of the equation.
100 + -100 + -49a2 = 0 + -100

Combine like terms: 100 + -100 = 0
0 + -49a2 = 0 + -100
-49a2 = 0 + -100

Combine like terms: 0 + -100 = -100
-49a2 = -100

Divide each side by '-49'.
a2 = 2.040816327

Simplifying
a2 = 2.040816327

Take the square root of each side:
a = {-1.428571429, 1.428571429}