(a-1)-(a-2)-(a-3)=a

Solution for (a-1)-(a-2)-(a-3)=a equation:

Simplifying
(a + -1) + -1(a + -2) + -1(a + -3) = a

Reorder the terms:
(-1 + a) + -1(a + -2) + -1(a + -3) = a

Remove parenthesis around (-1 + a)
-1 + a + -1(a + -2) + -1(a + -3) = a

Reorder the terms:
-1 + a + -1(-2 + a) + -1(a + -3) = a
-1 + a + (-2 * -1 + a * -1) + -1(a + -3) = a
-1 + a + (2 + -1a) + -1(a + -3) = a

Reorder the terms:
-1 + a + 2 + -1a + -1(-3 + a) = a
-1 + a + 2 + -1a + (-3 * -1 + a * -1) = a
-1 + a + 2 + -1a + (3 + -1a) = a

Reorder the terms:
-1 + 2 + 3 + a + -1a + -1a = a

Combine like terms: -1 + 2 = 1
1 + 3 + a + -1a + -1a = a

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

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

Solving
4 + -1a = 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.
4 + -1a + -1a = a + -1a

Combine like terms: -1a + -1a = -2a
4 + -2a = a + -1a

Combine like terms: a + -1a = 0
4 + -2a = 0

Add '-4' to each side of the equation.
4 + -4 + -2a = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -2a = 0 + -4
-2a = 0 + -4

Combine like terms: 0 + -4 = -4
-2a = -4

Divide each side by '-2'.
a = 2

Simplifying
a = 2