A÷(X-5)+B÷(X+2)=(5X-4)÷(X²-3X-10),试求A,B的值.
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A÷(X-5)+B÷(X+2)=(5X-4)÷(X²-3X-10),试求A,B的值.
A÷(X-5)+B÷(X+2)=(5X-4)÷(X²-3X-10),试求A,B的值.
A÷(X-5)+B÷(X+2)=(5X-4)÷(X²-3X-10),试求A,B的值.
A/(X-5)+B/(X+2)=(5X-4)/(X²-3X-10),
通分得:A(X+2)/(X+2)(X-5)+B(X-5)/(X-5)(X+2)=(5X-4)/(X+2)(X-5),
去分母得:A(X+2)+B(X-5)=5X-4
去括号得:AX+2A+BX-5B=5X-4
整理得;(A+B)X+2A-5B=5X-4
要使上面等式成立,则应有
A+B=5 2A-5B=-4
联立解得:A=3 B=2
原式通分得
[(x+2)A+(X-5)B]/(X-5)(X+2)=(5X-4)/[(X-5)(X+2)],分母相同可约去,得
(x+2)A+(X-5)B=5X-4
(A+B)X+(2A-5B)=5X-4,得
A+B=5①
2A-5B=-4②
①式左右两边乘以2得
2A+2B=10③
②-③得
-7B=-14得
B=2,...
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原式通分得
[(x+2)A+(X-5)B]/(X-5)(X+2)=(5X-4)/[(X-5)(X+2)],分母相同可约去,得
(x+2)A+(X-5)B=5X-4
(A+B)X+(2A-5B)=5X-4,得
A+B=5①
2A-5B=-4②
①式左右两边乘以2得
2A+2B=10③
②-③得
-7B=-14得
B=2,将B值代入①得
A=3
答A=3;B=2
有不懂的地方可以问我。O(∩_∩)O~
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A÷(X-5)+B÷(X+2)=(5X-4)÷(X²-3X-10)
[A*(X+2)+B(X-5)]/(X+2)(X-5)=(5X-4)/(X+2)(X-5)
(AX+2A+BX-5B)/(X+2)(X-5)=(5X-4)/(X+2)(X-5)
AX+2A+BX-5B=5X-4
(A+B)X+2A-5B=5X-4
A+B=5 2A-5B=-4
A=3 ,B=2
原式通分得
[(x+2)A+(X-5)B]/(X-5)(X+2)=(5X-4)/[(X-5)(X+2)],分母相同可约去,得
(x+2)A+(X-5)B=5X-4
(A+B)X+(2A-5B)=5X-4,得
A+B=5①
2A-5B=-4②
①式左右两边乘以2得
2A+2B=10③
②-③得
-7B=-14得
B=2,将B值代入①得
A=3
答A=3;B=2