初三数学,
已知1/a-1/b=2,求(5a+ab-5b)/(2a-ab-2b)
参考答案:解:1/a-1/b=2
b/ab-a/ab=2
(b-a)/ab=2
b-a=2ab
(5a+ab-5b)/(2a-ab-2b)
=[5a+1/2b-1/2a-5b]/[2a-1/2b+1/2a-2b]
=[9/2(a-b)]/[2/5(a-b)]
=9/5
已知1/a-1/b=2,求(5a+ab-5b)/(2a-ab-2b)
参考答案:解:1/a-1/b=2
b/ab-a/ab=2
(b-a)/ab=2
b-a=2ab
(5a+ab-5b)/(2a-ab-2b)
=[5a+1/2b-1/2a-5b]/[2a-1/2b+1/2a-2b]
=[9/2(a-b)]/[2/5(a-b)]
=9/5