> 数学 >
A
x+2
+
B
x−3
7x−11
x2−x−6
,试求A,B的值.
人气:453 ℃ 时间:2020-02-05 23:49:41
解答
A
x+2
+
B
x−3
=
A(x−3)+B(x+2)
(x+2)(x−3)
=
Ax−3A+Bx+2B
x2−x−6
=
(A+B)x+(−3A+2B)
x2−x−6
=
7x−11
x2−x−6

A+B=7
−3A+2B=−11

解得:A=5,B=2.
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