m^2+10m+21=0

Solution for m^2+10m+21=0 equation:

Simplifying
m2 + 10m + 21 = 0

Reorder the terms:
21 + 10m + m2 = 0

Solving
21 + 10m + m2 = 0

Solving for variable 'm'.

Factor a trinomial.
(7 + m)(3 + m) = 0

Subproblem 1
Set the factor '(7 + m)' equal to zero and attempt to solve:

Simplifying
7 + m = 0

Solving
7 + m = 0

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

Add '-7' to each side of the equation.
7 + -7 + m = 0 + -7

Combine like terms: 7 + -7 = 0
0 + m = 0 + -7
m = 0 + -7

Combine like terms: 0 + -7 = -7
m = -7

Simplifying
m = -7
Subproblem 2
Set the factor '(3 + m)' equal to zero and attempt to solve:

Simplifying
3 + m = 0

Solving
3 + m = 0

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

Add '-3' to each side of the equation.
3 + -3 + m = 0 + -3

Combine like terms: 3 + -3 = 0
0 + m = 0 + -3
m = 0 + -3

Combine like terms: 0 + -3 = -3
m = -3

Simplifying
m = -3
Solution
m = {-7, -3}