5x^2+21x+16=0

Solution for 5x^2+21x+16=0 equation:

Simplifying
5x2 + 21x + 16 = 0

Reorder the terms:
16 + 21x + 5x2 = 0

Solving
16 + 21x + 5x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(16 + 5x)(1 + x) = 0

Subproblem 1
Set the factor '(16 + 5x)' equal to zero and attempt to solve:

Simplifying
16 + 5x = 0

Solving
16 + 5x = 0

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

Add '-16' to each side of the equation.
16 + -16 + 5x = 0 + -16

Combine like terms: 16 + -16 = 0
0 + 5x = 0 + -16
5x = 0 + -16

Combine like terms: 0 + -16 = -16
5x = -16

Divide each side by '5'.
x = -3.2

Simplifying
x = -3.2
Subproblem 2
Set the factor '(1 + x)' equal to zero and attempt to solve:

Simplifying
1 + x = 0

Solving
1 + x = 0

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

Add '-1' to each side of the equation.
1 + -1 + x = 0 + -1

Combine like terms: 1 + -1 = 0
0 + x = 0 + -1
x = 0 + -1

Combine like terms: 0 + -1 = -1
x = -1

Simplifying
x = -1
Solution
x = {-3.2, -1}