a)
Mẫu số chung 2 phân số: 7239
$\frac{56}{57}=\frac{56\cdot127}{57\cdot127}=\frac{7112}{7239}$
$\frac{124}{127}=\frac{124\cdot57}{127\cdot57}=\frac{7068}{7239}$
Vì $7112>7068$ nên$\frac{7112}{7239}>\frac{7068}{7239}$
Vậy $\frac{56}{57}>\frac{124}{127}$
b)
Mẫu số chung 2 phân số: 8473
$\frac{39}{37}=\frac{39\cdot229}{37\cdot229}=\frac{8931}{8473}$
$\frac{231}{229}=\frac{231\cdot37}{229\cdot37}=\frac{8547}{8473}$
Vì $8931>8547$ nên$\frac{8931}{8473}>\frac{8547}{8473}$
Vậy $\frac{39}{37}>\frac{231}{229}$
c)
Mẫu số chung 2 phân số: 264
$\frac{45}{44}=\frac{45\cdot6}{44\cdot6}=\frac{270}{264}$
$\frac{29}{24}=\frac{29\cdot11}{24\cdot11}=\frac{319}{264}$
Vì $270<319$ nên$\frac{270}{264}<\frac{319}{264}$
Vậy $\frac{45}{44}<\frac{29}{24}$
56/57>124/127
39/37>231/229
45/44<29/24