(m+4)(m-4)=20

Solution for (m+4)(m-4)=20 equation:

Simplifying
(m + 4)(m + -4) = 20

Reorder the terms:
(4 + m)(m + -4) = 20

Reorder the terms:
(4 + m)(-4 + m) = 20

Multiply (4 + m) * (-4 + m)
(4(-4 + m) + m(-4 + m)) = 20
((-4 * 4 + m * 4) + m(-4 + m)) = 20
((-16 + 4m) + m(-4 + m)) = 20
(-16 + 4m + (-4 * m + m * m)) = 20
(-16 + 4m + (-4m + m2)) = 20

Combine like terms: 4m + -4m = 0
(-16 + 0 + m2) = 20
(-16 + m2) = 20

Solving
-16 + m2 = 20

Solving for variable 'm'.

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

Add '16' to each side of the equation.
-16 + 16 + m2 = 20 + 16

Combine like terms: -16 + 16 = 0
0 + m2 = 20 + 16
m2 = 20 + 16

Combine like terms: 20 + 16 = 36
m2 = 36

Simplifying
m2 = 36

Take the square root of each side:
m = {-6, 6}