So sánh
a) \(\dfrac{17}{30}\)và \(\dfrac{51}{92}\)
b) \(-\dfrac{45}{47}\)và \(\dfrac{31}{-30}\)
c) \(\dfrac{22}{67}\)và \(\dfrac{51}{152}\)
d) \(-\dfrac{17}{39};\dfrac{18}{-39}\)và \(-\dfrac{17}{41}\)
e) \(\dfrac{42}{-37}\)và \(-\dfrac{56}{43}\)
a: \(\dfrac{17}{30}=\dfrac{1564}{30\cdot92}\)
\(\dfrac{51}{92}=\dfrac{1530}{30\cdot92}\)
mà 1564>1530
nên 17/30>51/92
b: \(\dfrac{-45}{47}>-1>-\dfrac{31}{30}\)
c: \(\dfrac{67}{22}=3+\dfrac{1}{22}\)
\(\dfrac{152}{51}=3+\dfrac{1}{51}\)
mà 1/22>1/51
nên 67/22>152/51
=>22/67<51/152
d: 17/39>17/41
nên -17/39<-17/41
=>-18/39<-17/39<-17/41