Odd Boolean Results

I'm new to boolean algebra and having problems simplifying expressions with odd number terms, Expressions such as: 1. A'B'C'D + A'B'CD + AB'C'D + AB'CD + ABC'D 2. A'BC + AB'C' + A'B'C' + AB'C + ABC Here is my logic for both expressions: A'B'C'D + A'B'CD + AB'C'D + AB'CD + ABC'D A'B'D'(C+C') + AB'D(C+C') + ABC'D A'B'D + AB'D + ABC'D B'D(A'+A) + ABC'D B'D + ABC'D I never touch the last term, and I don't know what rule I'm missing. Same thing happens on the second expression: A'BC + AB'C' + A'B'C' + AB'C + ABC A'BC + B'C'(A+A') + AC(B'+B) A'BC + B'C + AC Again, one term untouched. The result should be AC'D + B'D For 2. The result should be B'C + BC + AC I could maybe use Karnaugh maps but I also would like to understand the algebra logic.