42=2.1x

Solution for 42=2.1x equation:

Simplifying
42 = 2.1x

Solving
42 = 2.1x

Solving for variable 'x'.

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

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

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

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

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

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

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

Simplifying
x = 20