(a-2b+3a-b)-(5a-7b)=

Solution for (a-2b+3a-b)-(5a-7b)= equation:

Simplifying
(a + -2b + 3a + -1b) + -1(5a + -7b) = 0

Reorder the terms:
(a + 3a + -2b + -1b) + -1(5a + -7b) = 0

Combine like terms: a + 3a = 4a
(4a + -2b + -1b) + -1(5a + -7b) = 0

Combine like terms: -2b + -1b = -3b
(4a + -3b) + -1(5a + -7b) = 0

Remove parenthesis around (4a + -3b)
4a + -3b + -1(5a + -7b) = 0
4a + -3b + (5a * -1 + -7b * -1) = 0
4a + -3b + (-5a + 7b) = 0

Reorder the terms:
4a + -5a + -3b + 7b = 0

Combine like terms: 4a + -5a = -1a
-1a + -3b + 7b = 0

Combine like terms: -3b + 7b = 4b
-1a + 4b = 0

Solving
-1a + 4b = 0

Solving for variable 'a'.

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

Add '-4b' to each side of the equation.
-1a + 4b + -4b = 0 + -4b

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

Divide each side by '-1'.
a = 4b

Simplifying
a = 4b