3p^2-2p-21=0

Solution for 3p^2-2p-21=0 equation:

Simplifying
3p2 + -2p + -21 = 0

Reorder the terms:
-21 + -2p + 3p2 = 0

Solving
-21 + -2p + 3p2 = 0

Solving for variable 'p'.

Factor a trinomial.
(-7 + -3p)(3 + -1p) = 0

Subproblem 1
Set the factor '(-7 + -3p)' equal to zero and attempt to solve:

Simplifying
-7 + -3p = 0

Solving
-7 + -3p = 0

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

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

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

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

Divide each side by '-3'.
p = -2.333333333

Simplifying
p = -2.333333333
Subproblem 2
Set the factor '(3 + -1p)' equal to zero and attempt to solve:

Simplifying
3 + -1p = 0

Solving
3 + -1p = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1p = 0 + -3

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

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

Divide each side by '-1'.
p = 3

Simplifying
p = 3
Solution
p = {-2.333333333, 3}