1=a+13

Solution for 1=a+13 equation:

Simplifying
1 = a + 13

Reorder the terms:
1 = 13 + a

Solving
1 = 13 + a

Solving for variable 'a'.

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

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

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

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

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

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

Divide each side by '-1'.
a = -12

Simplifying
a = -12