42=2.1y

Solution for 42=2.1y equation:

Simplifying
42 = 2.1y

Solving
42 = 2.1y

Solving for variable 'y'.

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

Add '-2.1y' to each side of the equation.
42 + -2.1y = 2.1y + -2.1y

Combine like terms: 2.1y + -2.1y = 0.0
42 + -2.1y = 0.0

Add '-42' to each side of the equation.
42 + -42 + -2.1y = 0.0 + -42

Combine like terms: 42 + -42 = 0
0 + -2.1y = 0.0 + -42
-2.1y = 0.0 + -42

Combine like terms: 0.0 + -42 = -42
-2.1y = -42

Divide each side by '-2.1'.
y = 20

Simplifying
y = 20