The online calculator(not posting the name because I don't know if its's allowed) is giving me a different result and I can't find what I'm doing wrong:
Mine:
$A'BC' + A'BC + AB'C + ABC' + ABC= BC'(A'+A) + BC(A' + A) + AB'C= BC' + BC + AB'C= B(C' + C) + AB'C= B + AB'C$
The calculator's:
$=AC + BC' + BA'$
The two answers are equivalent:
$$\begin{align*} AC+BC'+BA'&=AC+B(A'+C')\\ &=AC+B(AC)'\\ &=AC(B+B')+B(AC)'\\ &=ACB+ACB'+B(AC)'\\ &=B\big(AC+(AC)'\big)+AB'C\\ &=B+AB'C \end{align*}$$