[질문] 곱셈공식좀보내주세요

(x+y)²=x²+2xy+y²/(x-y)²=x²-2xy+y²/(x+y)(x-y)=x²-y²/(x+a)(x+b)=x²+(a+b)x+ab/(ax+b)(cx+d)=acx²+(ad+bc)x+bd/(x+y)³=x³+3x²y+3xy²+y³/(x+y)(x²-xy+y²)=x³+y³