3a+1=13-a

Solution for 3a+1=13-a equation:

Simplifying
3a + 1 = 13 + -1a

Reorder the terms:
1 + 3a = 13 + -1a

Solving
1 + 3a = 13 + -1a

Solving for variable 'a'.

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

Add 'a' to each side of the equation.
1 + 3a + a = 13 + -1a + a

Combine like terms: 3a + a = 4a
1 + 4a = 13 + -1a + a

Combine like terms: -1a + a = 0
1 + 4a = 13 + 0
1 + 4a = 13

Add '-1' to each side of the equation.
1 + -1 + 4a = 13 + -1

Combine like terms: 1 + -1 = 0
0 + 4a = 13 + -1
4a = 13 + -1

Combine like terms: 13 + -1 = 12
4a = 12

Divide each side by '4'.
a = 3

Simplifying
a = 3