7u^2+52u+21=

Solution for 7u^2+52u+21= equation:

Simplifying
7u2 + 52u + 21 = 0

Reorder the terms:
21 + 52u + 7u2 = 0

Solving
21 + 52u + 7u2 = 0

Solving for variable 'u'.

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

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

Simplifying
7 + u = 0

Solving
7 + u = 0

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

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

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

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

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

Simplifying
3 + 7u = 0

Solving
3 + 7u = 0

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

Add '-3' to each side of the equation.
3 + -3 + 7u = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 7u = 0 + -3
7u = 0 + -3

Combine like terms: 0 + -3 = -3
7u = -3

Divide each side by '7'.
u = -0.4285714286

Simplifying
u = -0.4285714286
Solution
u = {-7, -0.4285714286}