Question

[Phượng Phạm]

Quy đồng mẫu các phân số

f) \(\dfrac{165}{270}\) ; \(\dfrac{91}{156}\) ; \(\dfrac{210}{1134}\)

g) \(\dfrac{21}{9}\) ; \(\dfrac{120}{50}\) ; \(\dfrac{63}{54}\)

h) \(\dfrac{75}{500}\) ; \(\dfrac{150}{90}\) ; \(\dfrac{250}{900}\)

bài 18: tìm 2 số tự nhiên a, b biết rằng a + b = 128 và ƯCLN (a,b) = 16

nhanh + chi tiết = tick

Answer 1

[Nguyễn Thị Thương Hoài]

f, \(\dfrac{165}{270}\) = \(\dfrac{165:15}{270:15}\) = \(\dfrac{11}{18}\) = \(\dfrac{11\times6}{18\times6}\) = \(\dfrac{66}{108}\)

 \(\dfrac{91}{156}\) = \(\dfrac{91:13}{156:13}\) = \(\dfrac{7}{12}\) = \(\dfrac{7\times9}{12\times9}\) = \(\dfrac{63}{108}\)

\(\dfrac{210}{1134}\) = \(\dfrac{210:42}{1134:42}\) = \(\dfrac{5}{27}\) =  \(\dfrac{5\times4}{27\times4}\) = \(\dfrac{20}{108}\)

Answer 2

[Nguyễn Thị Thương Hoài]

g, \(\dfrac{21}{9}\) = \(\dfrac{21:3}{9:3}\) = \(\dfrac{7}{3}\) = \(\dfrac{7\times10}{3\times10}\) = \(\dfrac{70}{30}\)

     \(\dfrac{120}{50}\) =  \(\dfrac{120:10}{50:10}\) = \(\dfrac{12}{5}\) = \(\dfrac{12\times6}{5\times6}\) = \(\dfrac{72}{30}\)

       \(\dfrac{63}{54}\) = \(\dfrac{63:9}{54:9}\) = \(\dfrac{7}{6}\)  = \(\dfrac{7\times5}{6\times5}\) = \(\dfrac{35}{30}\)