1 .rút gọn rồi quy đồng
a , \(\frac{15}{90}\) ; \(\frac{120}{600}\) ;\(\frac{75}{150}\)
b, \(\frac{54}{90}\) ; \(\frac{180}{288}\) ; \(\frac{60}{135}\)
2 .quy đồng mẫu cac s phân số
a,\(\frac{24}{146}\)và\(\frac{6}{13}\)
b, \(\frac{7}{30}\) ;\(\frac{13}{60}\) ; \(\frac{9}{40}\)
c , \(\frac{17}{60}\) ; \(\frac{5}{18}\) ; \(\frac{64}{90}\)
d, \(\frac{4}{7}\) ; \(\frac{8}{9}\) ; \(\frac{10}{21}\)
1)
a)15/90 = 1/6, 120/600=1/5, 75/150=1/5 mau so chung=30
1/6=5/30
1/5=6/30
1/5=6/30
b)54/90=3/5, 180/288=5/8, 60/135=4/9
3/5=3*8*9/5*8*9=216/360
5/8=5*5*9/5*8*9=225/360
4/9=4*8*5/5*8*9=160/360
bai 2 ban tu lam di,mk met roi