a(b+3)+7(b+3)=0

Solution for a(b+3)+7(b+3)=0 equation:

Simplifying
a(b + 3) + 7(b + 3) = 0

Reorder the terms:
a(3 + b) + 7(b + 3) = 0
(3 * a + b * a) + 7(b + 3) = 0
(3a + ab) + 7(b + 3) = 0

Reorder the terms:
3a + ab + 7(3 + b) = 0
3a + ab + (3 * 7 + b * 7) = 0
3a + ab + (21 + 7b) = 0

Reorder the terms:
21 + 3a + ab + 7b = 0

Solving
21 + 3a + ab + 7b = 0

Solving for variable 'a'.

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

Add '-21' to each side of the equation.
21 + 3a + ab + -21 + 7b = 0 + -21

Reorder the terms:
21 + -21 + 3a + ab + 7b = 0 + -21

Combine like terms: 21 + -21 = 0
0 + 3a + ab + 7b = 0 + -21
3a + ab + 7b = 0 + -21

Combine like terms: 0 + -21 = -21
3a + ab + 7b = -21

Add '-7b' to each side of the equation.
3a + ab + 7b + -7b = -21 + -7b

Combine like terms: 7b + -7b = 0
3a + ab + 0 = -21 + -7b
3a + ab = -21 + -7b

Reorder the terms:
21 + 3a + ab + 7b = -21 + -7b + 21 + 7b

Reorder the terms:
21 + 3a + ab + 7b = -21 + 21 + -7b + 7b

Combine like terms: -21 + 21 = 0
21 + 3a + ab + 7b = 0 + -7b + 7b
21 + 3a + ab + 7b = -7b + 7b

Combine like terms: -7b + 7b = 0
21 + 3a + ab + 7b = 0

The solution to this equation could not be determined.