giúp ppppppppppppppppppppppppppppp p

`a)`

`A=17/5×(-31/125)×1/2×10/17×(-1/23)`

`A=-527/625×1/2×10/17×(-1/23)`

`A=-527/1250×10/17×(-1/23)`

`A=-31/125×(-1/23)`

`A=31/2875`

Vậy `A=31/2875`

`b)`

`B=17/23×8/16×23/17×3/4×(-86)`

`B=17/46×23/17×3/4×(-86)`

`B=1/2×3/4×(-86)`

`B=3/8×(-86)`

`B=-129/4`

Vậy `B=-129/4`

`c)`

`C=14/27×81/91×5/6×69/125×5/23`

`C=6/13×5/6×69/125×5/23`

`C=5/13×69/125×5/23`

`C=69/325×5/23`

`C=3/65`

Vậy `C=3/65`