100=y+(y*.2)

Solution for 100=y+(y*.2) equation:

Simplifying
100 = y + (y * 0.2)

Reorder the terms for easier multiplication:
100 = y + (0.2y)

Combine like terms: y + (0.2y) = 1.2y
100 = 1.2y

Solving
100 = 1.2y

Solving for variable 'y'.

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

Add '-1.2y' to each side of the equation.
100 + -1.2y = 1.2y + -1.2y

Combine like terms: 1.2y + -1.2y = 0.0
100 + -1.2y = 0.0

Add '-100' to each side of the equation.
100 + -100 + -1.2y = 0.0 + -100

Combine like terms: 100 + -100 = 0
0 + -1.2y = 0.0 + -100
-1.2y = 0.0 + -100

Combine like terms: 0.0 + -100 = -100
-1.2y = -100

Divide each side by '-1.2'.
y = 83.33333333

Simplifying
y = 83.33333333