[질문] 10가나주요공식몇개만

곱셈공식(a+b)2=a2+2ab+b 2(a-b)2=a2-2ab+b2(a+b)(a-b)=a2-b2(x+a)(x+b)=x2+(a+b)x+ab (ax+b)(cx+d)=acx2+(ad+bc)x+bd