2x+(x-0.6)=21

Solution for 2x+(x-0.6)=21 equation:

Simplifying
2x + (x + -0.6) = 21

Reorder the terms:
2x + (-0.6 + x) = 21

Remove parenthesis around (-0.6 + x)
2x + -0.6 + x = 21

Reorder the terms:
-0.6 + 2x + x = 21

Combine like terms: 2x + x = 3x
-0.6 + 3x = 21

Solving
-0.6 + 3x = 21

Solving for variable 'x'.

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

Add '0.6' to each side of the equation.
-0.6 + 0.6 + 3x = 21 + 0.6

Combine like terms: -0.6 + 0.6 = 0.0
0.0 + 3x = 21 + 0.6
3x = 21 + 0.6

Combine like terms: 21 + 0.6 = 21.6
3x = 21.6

Divide each side by '3'.
x = 7.2

Simplifying
x = 7.2