7a^2-28a=0

Solution for 7a^2-28a=0 equation:

Simplifying
7a2 + -28a = 0

Reorder the terms:
-28a + 7a2 = 0

Solving
-28a + 7a2 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '7a'.
7a(-4 + a) = 0

Ignore the factor 7.
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 '(-4 + a)' equal to zero and attempt to solve:

Simplifying
-4 + a = 0

Solving
-4 + a = 0

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

Add '4' to each side of the equation.
-4 + 4 + a = 0 + 4

Combine like terms: -4 + 4 = 0
0 + a = 0 + 4
a = 0 + 4

Combine like terms: 0 + 4 = 4
a = 4

Simplifying
a = 4
Solution
a = {0, 4}