4a+6a+3-9=15

Solution for 4a+6a+3-9=15 equation:

Simplifying
4a + 6a + 3 + -9 = 15

Reorder the terms:
3 + -9 + 4a + 6a = 15

Combine like terms: 3 + -9 = -6
-6 + 4a + 6a = 15

Combine like terms: 4a + 6a = 10a
-6 + 10a = 15

Solving
-6 + 10a = 15

Solving for variable 'a'.

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

Add '6' to each side of the equation.
-6 + 6 + 10a = 15 + 6

Combine like terms: -6 + 6 = 0
0 + 10a = 15 + 6
10a = 15 + 6

Combine like terms: 15 + 6 = 21
10a = 21

Divide each side by '10'.
a = 2.1

Simplifying
a = 2.1