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\(a,3\dfrac{4}{5}+2\dfrac{1}{5}=\dfrac{19}{5}+\dfrac{11}{5}=\dfrac{30}{5}=6\\ b,7\dfrac{2}{9}-2\dfrac{1}{9}=\dfrac{65}{9}-\dfrac{19}{9}=\dfrac{46}{9}\\ c,5-2\dfrac{4}{11}=5-\dfrac{26}{11}=\dfrac{29}{11}\\ d,5\dfrac{1}{2}-2\dfrac{1}{3}+2\dfrac{1}{6}=\dfrac{11}{2}-\dfrac{7}{3}+\dfrac{13}{6}=\dfrac{32}{6}=\dfrac{16}{3}\\ e,3\dfrac{4}{5}\times2\dfrac{1}{5}=\dfrac{19}{5}\times\dfrac{11}{5}=\dfrac{209}{25}\\ f,7\dfrac{2}{9}:2\dfrac{1}{9}=\dfrac{65}{9}:\dfrac{19}{9}=\dfrac{65}{9}\times\dfrac{9}{19}=\dfrac{65}{19}\\ g,5\times2\dfrac{4}{11}=5\times\dfrac{26}{11}=\dfrac{130}{11}\\ h,5:2\dfrac{4}{1}=5:8=\dfrac{5}{8}\)
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\(a,4\dfrac{1}{4}-2=\dfrac{17}{4}-2=\dfrac{9}{4};\dfrac{5}{8}+2\dfrac{3}{5}=\dfrac{5}{8}+\dfrac{13}{5}=\dfrac{129}{40}\\ b,4\dfrac{4}{9}:2=\dfrac{40}{9}\cdot\dfrac{1}{2}=\dfrac{20}{9};\dfrac{2}{3}+3\dfrac{1}{6}=\dfrac{2}{3}+\dfrac{19}{6}=\dfrac{23}{6}\\ c,3\dfrac{1}{5}+2=\dfrac{9}{5}+2=\dfrac{19}{5};\dfrac{3}{5}-2\dfrac{4}{5}=\dfrac{3}{5}-\dfrac{14}{5}=-\dfrac{11}{5}\)
\(d,5\dfrac{1}{7}-2=\dfrac{36}{7}-2=\dfrac{22}{7};\dfrac{4}{5}:1\dfrac{1}{5}=\dfrac{4}{5}:\dfrac{6}{5}=\dfrac{2}{3}\\ e,2\dfrac{3}{5}+1=\dfrac{13}{5}+1=\dfrac{18}{5};\dfrac{1}{4}\cdot2\dfrac{2}{3}=\dfrac{1}{4}\cdot\dfrac{8}{3}=\dfrac{2}{3}\\ f,4\dfrac{1}{3}\cdot1=\dfrac{13}{3};\dfrac{1}{2}+5\dfrac{2}{7}=\dfrac{1}{2}+\dfrac{37}{7}=\dfrac{81}{14}\)
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a) \(1\frac{1}{2}+1\frac{1}{3}=\left(1+1\right)\frac{1}{2}+\frac{1}{3}=2+\frac{5}{6}=2\frac{5}{6}\)
b) \(2\frac{2}{3}-1\frac{4}{7}=\left(2-1\right)\frac{2}{3}-\frac{4}{7}=1+\frac{2}{21}=1\frac{2}{21}\)
c) \(2\frac{2}{3}\times5\frac{1}{4}=\frac{8}{3}\times\frac{21}{4}=14\)
d) \(3\frac{1}{2}:2\frac{1}{4}=\frac{7}{2}:\frac{9}{4}=\frac{7}{2}\times\frac{4}{9}=\frac{14}{9}\)
a) \(1\frac{1}{2}+1\frac{1}{3}=\frac{3}{2}+\frac{4}{3}=\frac{17}{6}\)
b) \(2\frac{2}{3}-1\frac{4}{7}=\frac{8}{3}-\frac{11}{4}=\frac{23}{21}\)
c) \(2\frac{2}{3}\times5\frac{1}{4}=\frac{8}{3}\times\frac{21}{4}=14\)
d) \(3\frac{1}{2}\div2\frac{1}{4}=\frac{7}{2}\div\frac{9}{4}=\frac{14}{9}\)
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Bài 1: tính: a) 8 và 5/9 : 5 và 1/2 b) 7 và 3/4 - 2 và 1/8 c) 1 và 3/4 x 2 và 5/6 d) 7 - 2 và 2/3 e) 2 và 3/7 x 1 và 3/4 g) 5 và 1/3 : 3 và 1/5 Bài 2: tìm X: X : 3 và 1/3= 2 và 2/5 + 7/10 Và là biểu thị cho hỗn số nhé
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Bài 1
a) 3 2/5 - 1/2
= 17/5 - 1/2
= 34/10 - 5/10
= 29/10
b) 4/5 + 1/5 × 3/4
= 4/5 + 3/20
= 16/20 + 3/20
= 19/20
c) 3 1/2 × 1 1/7
= 7/2 × 8/7
= 4
d) 4 1/6 : 2 1/3
= 25/6 : 7/3
= 25/14
Bài 2
a) 3 × 1/2 + 1/4 × 1/3
= 3/2 + 1/12
= 18/12 + 1/12
= 19/12
b) 1 4/5 - 2/3 : 2 1/3
= 9/5 - 2/3 : 7/3
= 9/5 - 2/7
= 63/35 - 10/35
= 53/35
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a) \(3\dfrac{1}{2}-1\dfrac{1}{4}\times1\dfrac{5}{6}\)
\(=\dfrac{7}{2}-\dfrac{5}{4}\times\dfrac{11}{6}\)
\(=\dfrac{7}{2}-\dfrac{55}{24}\)
\(=\dfrac{84}{24}-\dfrac{55}{24}\)
\(=\dfrac{29}{24}\)
b) \(2\dfrac{5}{6}+1\dfrac{2}{3}\div3\dfrac{3}{4}\)
\(=\dfrac{17}{6}+\dfrac{5}{3}\div\dfrac{15}{4}\)
\(=\dfrac{17}{6}+\dfrac{5}{3}\times\dfrac{4}{15}\)
\(=\dfrac{17}{6}+\dfrac{4}{9}\)
\(=\dfrac{153}{54}+\dfrac{24}{54}\)
\(=\dfrac{59}{18}\)
Lời giải:
Tỉ số phần trăm giữa 2 và 1/2 là:
$2: \frac{1}{2}\times 100=400$ (%)