63a-21a^3=

Solution for 63a-21a^3= equation:

Simplifying
63a + -21a3 = 0

Solving
63a + -21a3 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '21a'.
21a(3 + -1a2) = 0

Ignore the factor 21.
Subproblem 1
Set the factor 'a' equal to zero and attempt to solve:

Simplifying
a = 0

Solving
a = 0

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

Simplifying
a = 0
Subproblem 2
Set the factor '(3 + -1a2)' equal to zero and attempt to solve:

Simplifying
3 + -1a2 = 0

Solving
3 + -1a2 = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1a2 = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1a2 = 0 + -3
-1a2 = 0 + -3

Combine like terms: 0 + -3 = -3
-1a2 = -3

Divide each side by '-1'.
a2 = 3

Simplifying
a2 = 3

Take the square root of each side:
a = {-1.732050808, 1.732050808}
Solution
a = {0, -1.732050808, 1.732050808}