9分之7+10分之3-9分之2+10分之17 怎么简算

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7/9 +3/10-2/9 +17/10
=（晌大7/9-2/9）+（宴掘竖散前3/10+17/10）
=5/9 +2
=2又5/9

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=(7/9-2/9)+(3/10+17/10)
=5/9+2
=23/9

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=(7/9-2/9)+(3/10+17/10)
=5/9+2
=23/9

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7/9+3/派凳10-2/9+17/10
=70/脊羡汪90+27/90-20/90+153/90
=230/樱仔90
=23/9

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