a+(2-1)b-1=4

Solution for a+(2-1)b-1=4 equation:

Simplifying
a + (2 + -1) * b + -1 = 4

Combine like terms: 2 + -1 = 1
a + (1) * b + -1 = 4

Reorder the terms:
-1 + a + 1b = 4

Solving
-1 + a + 1b = 4

Solving for variable 'a'.

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

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

Reorder the terms:
-1 + 1 + a + 1b = 4 + 1

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

Combine like terms: 4 + 1 = 5
a + 1b = 5

Add '-1b' to each side of the equation.
a + 1b + -1b = 5 + -1b

Combine like terms: 1b + -1b = 0
a + 0 = 5 + -1b
a = 5 + -1b

Simplifying
a = 5 + -1b