-21-6a+5a=3a-5a

Solution for -21-6a+5a=3a-5a equation:

Simplifying
-21 + -6a + 5a = 3a + -5a

Combine like terms: -6a + 5a = -1a
-21 + -1a = 3a + -5a

Combine like terms: 3a + -5a = -2a
-21 + -1a = -2a

Solving
-21 + -1a = -2a

Solving for variable 'a'.

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

Add '2a' to each side of the equation.
-21 + -1a + 2a = -2a + 2a

Combine like terms: -1a + 2a = 1a
-21 + 1a = -2a + 2a

Combine like terms: -2a + 2a = 0
-21 + 1a = 0

Add '21' to each side of the equation.
-21 + 21 + 1a = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 1a = 0 + 21
1a = 0 + 21

Combine like terms: 0 + 21 = 21
1a = 21

Divide each side by '1'.
a = 21

Simplifying
a = 21