`1.`
`a)`
Ta có:`17/30=(17.3)/(30.3)=51/90`
Ta có:`90<92`
`⇒51/90>51/92`
`⇒17/30>51/92`
Vậy `17/30>51/92`
`b)`
Ta có:`(-3)/5=[(-3).3]/(5.3)=(-9)/15`
Ta có:`15<23`
`⇒(-9)/15<(-9)/23`
`⇒(-3)/5<(-9)/23`
Vậy `(-3)/5<(-9)/23`
`2.`
`a)`
Ta có:`1313/2727=(13.101)/(27.101)=13/27`
`⇒13/27=1313/2727`
Vậy `13/27=1313/2727`
`b)`
Ta có:`(-151515)/232323=[(-15).10101]/(23.10101)=(-15)/23`
`⇒(-15)/23=(-151515)/232323`
Vậy `(-15)/23=(-151515)/232323`