(m-3)(4m+12)=0

Solution for (m-3)(4m+12)=0 equation:

Simplifying
(m + -3)(4m + 12) = 0

Reorder the terms:
(-3 + m)(4m + 12) = 0

Reorder the terms:
(-3 + m)(12 + 4m) = 0

Multiply (-3 + m) * (12 + 4m)
(-3(12 + 4m) + m(12 + 4m)) = 0
((12 * -3 + 4m * -3) + m(12 + 4m)) = 0
((-36 + -12m) + m(12 + 4m)) = 0
(-36 + -12m + (12 * m + 4m * m)) = 0
(-36 + -12m + (12m + 4m2)) = 0

Combine like terms: -12m + 12m = 0
(-36 + 0 + 4m2) = 0
(-36 + 4m2) = 0

Solving
-36 + 4m2 = 0

Solving for variable 'm'.

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

Add '36' to each side of the equation.
-36 + 36 + 4m2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + 4m2 = 0 + 36
4m2 = 0 + 36

Combine like terms: 0 + 36 = 36
4m2 = 36

Divide each side by '4'.
m2 = 9

Simplifying
m2 = 9

Take the square root of each side:
m = {-3, 3}