-9=a-7+1

Solution for -9=a-7+1 equation:

Simplifying
-9 = a + -7 + 1

Reorder the terms:
-9 = -7 + 1 + a

Combine like terms: -7 + 1 = -6
-9 = -6 + a

Solving
-9 = -6 + 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.
-9 + -1a = -6 + a + -1a

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

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

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

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

Divide each side by '-1'.
a = -3

Simplifying
a = -3