已知代数式a+b/a-b=2,那么代数式(3a+3b/5a-5b)-(3a-3b/2a+ab)

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已知代数式a+b/a-b=2,那么代数式(3a+3b/5a-5b)-(3a-3b/2a+ab)

已知代数式a+b/a-b=2,那么代数式(3a+3b/5a-5b)-(3a-3b/2a+ab)
已知代数式a+b/a-b=2,那么代数式(3a+3b/5a-5b)-(3a-3b/2a+ab)

已知代数式a+b/a-b=2,那么代数式(3a+3b/5a-5b)-(3a-3b/2a+ab)
题目打错了,最后应该是2b吧
(3a+3b/5a-5b) = 3(a+b)/5(a-b) =3/5X(a+b/a-b) = 3/5x 2 = 6/5
(3a-3b/2a+2b) = 3(a-b)/2(a+b ) = 3/2x(a-b/a+b) = 3/2x1/2 = 3/4
所以(3a+3b/5a-5b)-(3a-3b/2a+2b) = 6/5-3/4 = 9/20 (小数的话是0.45)

因为(a+b)/(a-b)=2,所以:(a-b)/(a+b)=1/2
(3a+3b)/(5a-5b)-(3a-3b)/2(a+b)
=3/5*(a+b)/(a-b)-3/2*(a-b)/(a+b)
=3/5*2-3/2*1/2
=6/5-3/4=3/4