化简分式:2a2+3a+2a+1−a2−a−5a+2−3a2−4a−5a−2+2a2−8a+5a−3.
问题描述:
化简分式:
−2a2+3a+2 a+1
−
a2−a−5 a+2
+3a2−4a−5 a−2
. 2a2−8a+5 a−3
答
2a2+3a+2a+1−a2−a−5a+2−3a2−4a−5a−2+2a2−8a+5a−3=(2a+1)+1a+1-(a-3)-1a+2-(3a+2)+1a−2+(2a-2)-1a−3=[(2a+1)-(a-3)-(3a+2)+(2a-2)]+(1a+1-1a+2+1a−2-1a−3)=1a+1-1a+2+1a−2-1a−3=1(a...
答案解析:直接通分计算较繁,先把每个假分式化成整式与真分式之和的形式,再化简将简便得多.
考试点:分式的加减法.
知识点:本题考查了分式的加减运算,难度较大.本题的关键是正确地将假分式写成整式与真分式之和的形式.