7u^3=3u

Solution for 7u^3=3u equation:

Simplifying
7u3 = 3u

Solving
7u3 = 3u

Solving for variable 'u'.

Reorder the terms:
-3u + 7u3 = 3u + -3u

Combine like terms: 3u + -3u = 0
-3u + 7u3 = 0

Factor out the Greatest Common Factor (GCF), 'u'.
u(-3 + 7u2) = 0

Subproblem 1
Set the factor 'u' equal to zero and attempt to solve:

Simplifying
u = 0

Solving
u = 0

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

Simplifying
u = 0
Subproblem 2
Set the factor '(-3 + 7u2)' equal to zero and attempt to solve:

Simplifying
-3 + 7u2 = 0

Solving
-3 + 7u2 = 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 + 7u2 = 0 + 3

Combine like terms: -3 + 3 = 0
0 + 7u2 = 0 + 3
7u2 = 0 + 3

Combine like terms: 0 + 3 = 3
7u2 = 3

Divide each side by '7'.
u2 = 0.4285714286

Simplifying
u2 = 0.4285714286

Take the square root of each side:
u = {-0.654653671, 0.654653671}
Solution
u = {0, -0.654653671, 0.654653671}