3a+6=4a-9

Solution for 3a+6=4a-9 equation:

Simplifying
3a + 6 = 4a + -9

Reorder the terms:
6 + 3a = 4a + -9

Reorder the terms:
6 + 3a = -9 + 4a

Solving
6 + 3a = -9 + 4a

Solving for variable 'a'.

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

Add '-4a' to each side of the equation.
6 + 3a + -4a = -9 + 4a + -4a

Combine like terms: 3a + -4a = -1a
6 + -1a = -9 + 4a + -4a

Combine like terms: 4a + -4a = 0
6 + -1a = -9 + 0
6 + -1a = -9

Add '-6' to each side of the equation.
6 + -6 + -1a = -9 + -6

Combine like terms: 6 + -6 = 0
0 + -1a = -9 + -6
-1a = -9 + -6

Combine like terms: -9 + -6 = -15
-1a = -15

Divide each side by '-1'.
a = 15

Simplifying
a = 15