问题描述: 已知:X的平方-1/(X-2)(X-3)=A+B/(X-2)+C/X-3,求ABC的值 1个回答 分类:数学 2014-12-15 问题解答: 我来补答 (x^2-1)/{(x-2)(x-3) } = A + B/(x-2) + C(x-3)等式右边统分:{A(x-2)(x-3) + B(x-3) + C(x-2)} / {(x-2)(x-3)}= {A(x^2-5x+6) + B(x-3) + C(x-2)} / {(x-2)(x-3)}= {Ax^2-5Ax+6A + Bx-3B + Cx-2C} / {(x-2)(x-3)}= {Ax^2+(-5A+B+C)x+(6A-3B-2C)} / {(x-2)(x-3)}分母与等式左边一致,将分子与等式左边分子比较得:A=1-5A+B+C=06A-3B-2C=-1解得:A=1,B=-3,C=8 展开全文阅读