Factor completely: ac + a + bc – bd – ad + b.
ac + a + bc – bd – ad + b
= ac – ad + a + bc – bd + b
= a(c – d + 1) + b(c – d + 1)
= (a + b)(c – d + 1)
= a(c – d + 1) + b(c – d + 1)
= (a + b)(c – d + 1)
Factor completely: ac + a + bc – bd – ad + b.