(ab+4a-6)-(ab-6)=0

Solution for (ab+4a-6)-(ab-6)=0 equation:

Simplifying
(ab + 4a + -6) + -1(ab + -6) = 0

Reorder the terms:
(-6 + 4a + ab) + -1(ab + -6) = 0

Remove parenthesis around (-6 + 4a + ab)
-6 + 4a + ab + -1(ab + -6) = 0

Reorder the terms:
-6 + 4a + ab + -1(-6 + ab) = 0
-6 + 4a + ab + (-6 * -1 + ab * -1) = 0
-6 + 4a + ab + (6 + -1ab) = 0

Reorder the terms:
-6 + 6 + 4a + ab + -1ab = 0

Combine like terms: -6 + 6 = 0
0 + 4a + ab + -1ab = 0
4a + ab + -1ab = 0

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

Solving
4a = 0

Solving for variable 'a'.

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

Divide each side by '4'.
a = 0

Simplifying
a = 0