x32x2的精選

問題詳情：已知x3+2x2-5x-6=(x+a)(x+b)(x+c),則a,b,c的值分別為()A.1,2,3          B.1,-2,-3C.1,-2,3         D.1,2,-3【回答】C解析∵(x+a)(x+b)(x+c)=x3+(a+b+c)x2+(ab+bc+ca)x+abc=x3+2x2-5x-6...