已知1/a-1/b=2,求代数式(-3a+4ab+3b)/(2a-3ab-2b)
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已知1/a-1/b=2,求代数式(-3a+4ab+3b)/(2a-3ab-2b)
已知1/a-1/b=2,求代数式(-3a+4ab+3b)/(2a-3ab-2b)
已知1/a-1/b=2,求代数式(-3a+4ab+3b)/(2a-3ab-2b)
1/a-1/b=2
(b-a)/ab=2
b-a=2ab
(-3a+4ab+3b)/(2a-3ab-2b)
=[4ab+3(b-a)]/(-3ab-2(b-a))
=(4ab+6ab)/(-3ab-4ab)
=10ab/-7ab
=-10/7
(-3a+4ab+3b)/(2a-3ab-2b) 分子分母同时除以ab
=(-3/b+4+3/a)/(2/b-3-2/a)
=[3(1/a-1/b)+4]/[-2(1/a-1/b)-3]
=(6+4)/(-4-3)
=-10/7
1/a-1/b=2
则b-a=2ab
(-3a+4ab+3b)/(2a-3ab-2b)=[3(b-a)+4ab]/[-3ab-2(b-a)]=10ab/(-7ab)=-10/7