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b, \(\dfrac{7}{13}\) và \(\dfrac{17}{23}\)
\(\dfrac{7}{13}\) < \(\dfrac{7+10}{13+10}\) = \(\dfrac{17}{23}\)
Vậy \(\dfrac{7}{13}\) < \(\dfrac{17}{23}\)
\(\dfrac{12}{48}\) = \(\dfrac{12:12}{48:12}\) = \(\dfrac{1}{4}\)
\(\dfrac{13}{47}\) > \(\dfrac{13}{52}\) = \(\dfrac{13:13}{52:13}\) = \(\dfrac{1}{4}\)
Vậy \(\dfrac{12}{48}\) < \(\dfrac{13}{47}\)
c1: So sánh qua phần bù với 1: Ta có
1-7/13 = 6/13 , 1-17/23 = 6/23
Vì 6/13>6/23 nên 1/13<17/23
c2: Quy đồng mẫu số , ta có:
7/13=7x23 / 13x23= 161/299 , 17/23=17x13/23x13= 221/299
vì 161< 221 nên 7/13<17/23
c3. Cùng chia cả 2 ps cho 1 trong 2 phân số đó:
7/13:7/13=1 , 17/23:7/13 = 221/161
vì 1<221/161 nên 7/13<17/23
......Tk nha. mik trả lời đầu tiên
a; Cách một:
\(\dfrac{2}{9}\) = \(\dfrac{2\times2}{9\times2}\) = \(\dfrac{4}{18}\) < \(\dfrac{4}{10}\) Vậy \(\dfrac{2}{9}\) < \(\dfrac{4}{10}\)
\(\dfrac{4}{9}\) = \(\dfrac{4\times3}{9\times3}\) = \(\dfrac{12}{27}\); \(\dfrac{6}{10}\) = \(\dfrac{6\times2}{10\times2}\) = \(\dfrac{12}{20}\)
Vì \(\dfrac{12}{27}\) < \(\dfrac{12}{20}\) vậy \(\dfrac{4}{9}\) < \(\dfrac{12}{20}\)
\(\dfrac{3}{8}\) = \(\dfrac{3\times4}{8\times4}\) = \(\dfrac{12}{24}\); \(\dfrac{4}{7}\) = \(\dfrac{4\times3}{7\times3}\) = \(\dfrac{12}{21}\)
Vậy \(\dfrac{3}{8}\) < \(\dfrac{4}{7}\)
\(\dfrac{5}{9}\) = \(\dfrac{5\times7}{9\times7}\) = \(\dfrac{35}{63}\); \(\dfrac{7}{10}\) = \(\dfrac{7\times5}{10\times5}\) = \(\dfrac{35}{50}\)
Vì \(\dfrac{35}{63}\) < \(\dfrac{35}{50}\) vậy \(\dfrac{5}{9}\) < \(\dfrac{7}{10}\)
Cách hai:
a; \(\dfrac{2}{9}\) = \(\dfrac{2\times10}{9\times10}\) = \(\dfrac{20}{90}\); \(\dfrac{4}{10}\) = \(\dfrac{4\times9}{10\times9}\) = \(\dfrac{36}{90}\)
Vì \(\dfrac{20}{90}\) < \(\dfrac{36}{90}\) vậy \(\dfrac{2}{9}\) < \(\dfrac{4}{10}\)
b; \(\dfrac{4}{9}\) = \(\dfrac{4\times10}{9\times10}\) = \(\dfrac{40}{90}\); \(\dfrac{6}{10}\) = \(\dfrac{6\times9}{10\times9}\) = \(\dfrac{54}{90}\)
Vì \(\dfrac{40}{90}\) < \(\dfrac{54}{90}\) vậy \(\dfrac{4}{9}\) < \(\dfrac{6}{10}\)
c; \(\dfrac{3}{8}\) = \(\dfrac{3\times7}{8\times7}\) = \(\dfrac{21}{56}\); \(\dfrac{4}{7}\) = \(\dfrac{4\times8}{7\times8}\) = \(\dfrac{32}{56}\)
Vì \(\dfrac{21}{56}\) < \(\dfrac{32}{56}\) vậy \(\dfrac{3}{8}\) < \(\dfrac{4}{7}\)
d; \(\dfrac{5}{9}\) = \(\dfrac{5\times10}{9\times10}\) = \(\dfrac{50}{90}\); \(\dfrac{7}{10}\) = \(\dfrac{7\times9}{10\times9}\) = \(\dfrac{63}{90}\)
Vì \(\dfrac{50}{90}\) < \(\dfrac{63}{90}\) vậy \(\dfrac{5}{9}\) < \(\dfrac{7}{10}\)
a; Cách một:
\(\dfrac{2}{9}\) = \(\dfrac{2\times2}{9\times2}\) = \(\dfrac{4}{18}\) < \(\dfrac{4}{10}\) Vậy \(\dfrac{2}{9}\) < \(\dfrac{4}{10}\)
\(\dfrac{4}{9}\) = \(\dfrac{4\times3}{9\times3}\) = \(\dfrac{12}{27}\); \(\dfrac{6}{10}\) = \(\dfrac{6\times2}{10\times2}\) = \(\dfrac{12}{20}\)
Vì \(\dfrac{12}{27}\) < \(\dfrac{12}{20}\) vậy \(\dfrac{4}{9}\) < \(\dfrac{12}{20}\)
\(\dfrac{3}{8}\) = \(\dfrac{3\times4}{8\times4}\) = \(\dfrac{12}{24}\); \(\dfrac{4}{7}\) = \(\dfrac{4\times3}{7\times3}\) = \(\dfrac{12}{21}\)
Vậy \(\dfrac{3}{8}\) < \(\dfrac{4}{7}\)
\(\dfrac{5}{9}\) = \(\dfrac{5\times7}{9\times7}\) = \(\dfrac{35}{63}\); \(\dfrac{7}{10}\) = \(\dfrac{7\times5}{10\times5}\) = \(\dfrac{35}{50}\)
Vì \(\dfrac{35}{63}\) < \(\dfrac{35}{50}\) vậy \(\dfrac{5}{9}\) < \(\dfrac{7}{10}\)
Cách hai:
a; \(\dfrac{2}{9}\) = \(\dfrac{2\times10}{9\times10}\) = \(\dfrac{20}{90}\); \(\dfrac{4}{10}\) = \(\dfrac{4\times9}{10\times9}\) = \(\dfrac{36}{90}\)
Vì \(\dfrac{20}{90}\) < \(\dfrac{36}{90}\) vậy \(\dfrac{2}{9}\) < \(\dfrac{4}{10}\)
b; \(\dfrac{4}{9}\) = \(\dfrac{4\times10}{9\times10}\) = \(\dfrac{40}{90}\); \(\dfrac{6}{10}\) = \(\dfrac{6\times9}{10\times9}\) = \(\dfrac{54}{90}\)
Vì \(\dfrac{40}{90}\) < \(\dfrac{54}{90}\) vậy \(\dfrac{4}{9}\) < \(\dfrac{6}{10}\)
c; \(\dfrac{3}{8}\) = \(\dfrac{3\times7}{8\times7}\) = \(\dfrac{21}{56}\); \(\dfrac{4}{7}\) = \(\dfrac{4\times8}{7\times8}\) = \(\dfrac{32}{56}\)
Vì \(\dfrac{21}{56}\) < \(\dfrac{32}{56}\) vậy \(\dfrac{3}{8}\) < \(\dfrac{4}{7}\)
d; \(\dfrac{5}{9}\) = \(\dfrac{5\times10}{9\times10}\) = \(\dfrac{50}{90}\); \(\dfrac{7}{10}\) = \(\dfrac{7\times9}{10\times9}\) = \(\dfrac{63}{90}\)
Vì \(\dfrac{50}{90}\) < \(\dfrac{63}{90}\) vậy \(\dfrac{5}{9}\) < \(\dfrac{7}{10}\)
a, 3/4 và 4/5
\(\frac{3}{4}< \frac{4}{5}vì3.5< 4.4\)
b,2000/1000 và 2/5
ta có \(\frac{2000}{1000}=\frac{2}{1}>1\)và 2/5 < 1
Suy ra \(\frac{2000}{1000}>1>\frac{2}{5}\)
Vậy \(\frac{2000}{1000}>\frac{2}{5}\)
c,7/5 và 9/7
ta có \(\frac{7}{5}>\frac{9}{7}\)vì 7.7 > 5.9
a) 3/4 và 4/5
1 - 3/4 = 1/4
1 - 4/5 = 1/5
Vì 1/4 > 1/5 nên 3/4 < 4/5
b) 2000/1000 và 2/5
2000/1000 > 1
2/5 < 1
2000/1000 > 1 > 2/5 nên 2000/1000 > 2/5
c) 7/5 và 9/7
7/5 - 1 = 2/5
9/7 - 1 = 2/7
Vì 2/5 > 2/7 nên 7/5 > 9/7
Chúc bạn học tốt.
1 : 31/42 ; 32/42 ; 33/42 ; 34/42 ; 35/42 .
2 : chu vi = 125 m
3 : 12/13 <13/14
Kết bạn nhé
1.Đổi 5/7=30/42
6/7=36/42
Kết quả:31/42,32/42,33/42,34/42,35/42
2.Diện tích thửa ruộng là:
25x25=625m2
Chiều rông thửa ruộng là:
625:12,5=50m
Chu vi thửa ruộng là:
(12,5+50)x2=125m
3.12/13<13/14