6+z=21+(-2z)

Solution for 6+z=21+(-2z) equation:

Simplifying
6 + z = 21 + (-2z)

Solving
6 + z = 21 + (-2z)

Solving for variable 'z'.

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

Add '(2z)' to each side of the equation.
6 + z + (2z) = 21 + (-2z) + (2z)

Combine like terms: z + (2z) = 3z
6 + 3z = 21 + (-2z) + (2z)

Combine like terms: (-2z) + (2z) = 0
6 + 3z = 21 + 0
6 + 3z = 21

Add '-6' to each side of the equation.
6 + -6 + 3z = 21 + -6

Combine like terms: 6 + -6 = 0
0 + 3z = 21 + -6
3z = 21 + -6

Combine like terms: 21 + -6 = 15
3z = 15

Divide each side by '3'.
z = 5

Simplifying
z = 5