\(\dfrac{33}{38}:\dfrac{11}{19}=\dfrac{33\times19}{38\times11}=\dfrac{3\times1}{2\times1}=\dfrac{3}{2}\)

\(\frac{22\cdot13\cdot17}{55\cdot26\cdot51}\)

\(=\frac{22\cdot13\cdot17}{55\cdot13\cdot2\cdot3\cdot17}\)

\(=\frac{11\cdot2}{55\cdot2\cdot3}\)

\(=\frac{11}{55\cdot3}=\frac{11}{165}\)

\(\frac{22.13.17}{55.26.51}\) = \(\frac{2.11.13.17}{11.5.13.2.17.3}\) = \(\frac{1}{15}\) 

. là dấu nhân nhé

22 x 13 x 17

55 x 26 x 51

=      11 x 2 x 13 x 17

   11 x 5 x 13 x 2 x 17 x 3

= 1

   15

???

\(\frac{17}{13}\) :  \(\frac{51}{26}\) = \(\frac{17}{13}\) x \(\frac{26}{51}\) = \(\frac{1}{2}\) x \(\frac{2}{3}\) = \(\frac{1}{3}\)

 P/S : 17 mk rút gọn cho 51 còn 13 rút gọn cho 26 nha 

17 : 17 = 1 ; 51 : 17 = 3          13 : 13 = 1   ;      26 : 13 = 2

Cách làm :

\(\frac{17}{13}:\frac{51}{26}\)

\(=\frac{17}{13}×\)\(\frac{26}{51}\)

\(=\frac{442}{663}=\frac{2}{3}\)

\(\frac{6}{25}:\frac{21}{20}=\frac{8}{33};\frac{17}{13}:\frac{51}{26}=\frac{2}{3}\)

4/9 - 1/6 bằng 24/54 - 9/54 bằng 15

17/13 : 51/26 bằng 17/13 nhân 26/51 bằng 442/663

lớp 1 mà cậu

4.24.5²-(3³.18+3³.12)

=4.24.25-[27.(18+12)]

=(4.25).24-[27.30]

=100.24-810

=2400-810

=1590

4.24.5^2-(3^3.18+3^3.12)

31.15.7^2.4-31.49.40

1+2+3+4+5+6+7+8+9+10

1+3+5+7+9+11+13+15+19

2+6+10+14+22+23+26+34

5+8+11+14+17+20+23+26+29

1+6+11+16+21+26+31+36+41+47+51

10+13+16+19+22+25+28+31+34+37+40

5+7+9+11+13+15+17+3+8+13+18+23+28

4+7+10+13+16+19+5+9+13+17+21+25 = 1590

#HT#

17/13:51/26=17/13x26/51=2/3 

Bằng 2/3 

Ch mk 1 L-I-K-E nha/1

443 phần 663 nhé bn tk nha

1.1) 6

 1.2) 1/6
 

\(3\div\frac{1}{2}=3\times\frac{2}{1}=6\)

\(\frac{1}{2}\div3=\frac{1}{2}\times\frac{1}{3}=\frac{1}{6}\)

2.Tính theo mẫu :

b) \(\frac{6}{25}\div\frac{21}{20}=\frac{6}{25}\times\frac{20}{21}=\frac{6\times20}{25\times21}=\frac{2\times3\times4\times5}{5\times5\times3\times7}=\frac{8}{35}\)

\(\frac{40}{7}\times\frac{14}{5}=\frac{40\times14}{7\times5}=\frac{5\times8\times7\times2}{7\times5}=16\)

\(\frac{17}{13}\div\frac{51}{26}=\frac{17}{13}\times\frac{26}{51}=\frac{17\times13\times2}{13\times17\times3}=\frac{2}{3}\)

Chúc bạn hok tốt !

Bài 1:

\(3:\frac{1}{2}=3x2=6\)

\(\frac{1}{2}:3=\frac{1}{2}x\frac{1}{3}=\frac{1}{6}\)

Bài 2L

b) \(\frac{6}{25}:\frac{21}{20}=\frac{6}{25}\times\frac{20}{21}=\frac{2\times3\times4\times5}{5\times5\times3\times7}=\frac{8}{7}\)

\(\frac{40}{7}\times\frac{14}{5}=\frac{8\times5\times2\times7}{7\times5}=16\)

\(\frac{17}{13}:\frac{51}{26}=\frac{17}{13}\times\frac{26}{51}=\frac{17\times2\times13}{13\times17\times3}=\frac{2}{3}\)

9: \(=\dfrac{47}{51}\cdot\dfrac{17}{94}-\dfrac{47}{51}\cdot\dfrac{53}{91}-\dfrac{53}{91}\cdot\dfrac{91}{53}+\dfrac{53}{91}\cdot\dfrac{47}{51}\)

\(=\dfrac{1}{6}-1=-\dfrac{5}{6}\)

10: \(=\dfrac{13}{19}\cdot\dfrac{19}{26}-\dfrac{13}{19}\cdot\dfrac{71}{43}+\dfrac{71}{43}\cdot\dfrac{13}{19}-\dfrac{71}{43}\cdot\dfrac{86}{71}\)

\(=\dfrac{1}{2}-2=-\dfrac{3}{2}\)