y^2-21y+0=0

Solution for y^2-21y+0=0 equation:

Simplifying
y2 + -21y + 0 = 0

Reorder the terms:
0 + -21y + y2 = 0
Remove the zero:
-21y + y2 = 0

Solving
-21y + y2 = 0

Solving for variable 'y'.

Factor out the Greatest Common Factor (GCF), 'y'.
y(-21 + y) = 0

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

Simplifying
y = 0

Solving
y = 0

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

Simplifying
y = 0
Subproblem 2
Set the factor '(-21 + y)' equal to zero and attempt to solve:

Simplifying
-21 + y = 0

Solving
-21 + y = 0

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

Add '21' to each side of the equation.
-21 + 21 + y = 0 + 21

Combine like terms: -21 + 21 = 0
0 + y = 0 + 21
y = 0 + 21

Combine like terms: 0 + 21 = 21
y = 21

Simplifying
y = 21
Solution
y = {0, 21}