(3x+1)(x+3)=

Solution for (3x+1)(x+3)= equation:

Simplifying
(3x + 1)(x + 3) = 0

Reorder the terms:
(1 + 3x)(x + 3) = 0

Reorder the terms:
(1 + 3x)(3 + x) = 0

Multiply (1 + 3x) * (3 + x)
(1(3 + x) + 3x * (3 + x)) = 0
((3 * 1 + x * 1) + 3x * (3 + x)) = 0
((3 + 1x) + 3x * (3 + x)) = 0
(3 + 1x + (3 * 3x + x * 3x)) = 0
(3 + 1x + (9x + 3x2)) = 0

Combine like terms: 1x + 9x = 10x
(3 + 10x + 3x2) = 0

Solving
3 + 10x + 3x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(3 + x)(1 + 3x) = 0

Subproblem 1
Set the factor '(3 + x)' equal to zero and attempt to solve:

Simplifying
3 + x = 0

Solving
3 + x = 0

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

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

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

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

Simplifying
x = -3
Subproblem 2
Set the factor '(1 + 3x)' equal to zero and attempt to solve:

Simplifying
1 + 3x = 0

Solving
1 + 3x = 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 + 3x = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 3x = 0 + -1
3x = 0 + -1

Combine like terms: 0 + -1 = -1
3x = -1

Divide each side by '3'.
x = -0.3333333333

Simplifying
x = -0.3333333333
Solution
x = {-3, -0.3333333333}