2a-[(3a+4)-5]-a=5

Solution for 2a-[(3a+4)-5]-a=5 equation:

Simplifying
2a + -1[(3a + 4) + -5] + -1a = 5

Reorder the terms:
2a + -1[(4 + 3a) + -5] + -1a = 5

Remove parenthesis around (4 + 3a)
2a + -1[4 + 3a + -5] + -1a = 5

Reorder the terms:
2a + -1[4 + -5 + 3a] + -1a = 5

Combine like terms: 4 + -5 = -1
2a + -1[-1 + 3a] + -1a = 5
2a + [-1 * -1 + 3a * -1] + -1a = 5
2a + [1 + -3a] + -1a = 5

Reorder the terms:
1 + 2a + -3a + -1a = 5

Combine like terms: 2a + -3a = -1a
1 + -1a + -1a = 5

Combine like terms: -1a + -1a = -2a
1 + -2a = 5

Solving
1 + -2a = 5

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 + -1 + -2a = 5 + -1

Combine like terms: 1 + -1 = 0
0 + -2a = 5 + -1
-2a = 5 + -1

Combine like terms: 5 + -1 = 4
-2a = 4

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

Simplifying
a = -2