3(a+2)+a+15=15

Solution for 3(a+2)+a+15=15 equation:

Simplifying
3(a + 2) + a + 15 = 15

Reorder the terms:
3(2 + a) + a + 15 = 15
(2 * 3 + a * 3) + a + 15 = 15
(6 + 3a) + a + 15 = 15

Reorder the terms:
6 + 15 + 3a + a = 15

Combine like terms: 6 + 15 = 21
21 + 3a + a = 15

Combine like terms: 3a + a = 4a
21 + 4a = 15

Solving
21 + 4a = 15

Solving for variable 'a'.

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

Add '-21' to each side of the equation.
21 + -21 + 4a = 15 + -21

Combine like terms: 21 + -21 = 0
0 + 4a = 15 + -21
4a = 15 + -21

Combine like terms: 15 + -21 = -6
4a = -6

Divide each side by '4'.
a = -1.5

Simplifying
a = -1.5