z là gì vậy bn

A ) \(=\dfrac{2\times9\times11\times2\times19\times2}{11\times19\times9}=\dfrac{8}{1}=8\)

b)\(=\dfrac{2}{5}\times\left(\dfrac{4}{7}+\dfrac{9}{7}+\dfrac{8}{7}\right)=\dfrac{2}{5}\times\dfrac{21}{7}=\dfrac{2}{5}\times3=\dfrac{6}{5}\)

\(E=1.2.3+2.3.4+3.4.5+...+18.19.20\)

\(4E=1.2.3.4+2.3.4.4+3.4.5.4+...+18.19.20.4\)

\(4E=1.2.3.4+2.3.4.\left(5-1\right)+3.4.5.\left(6-2\right)+...+18.19.20.\left(21-17\right)\)

\(4E=1.2.3.4+2.3.4.5-1.2.3.4+3.4.5.6-2.3.4.5+...+18.19.20.21-17.18.19.20\)

\(4E=18.19.20.21\)

\(4E=143640\)

\(E=\frac{143640}{4}\)

\(E=35910\)

Chúc bạn học tốt ~ 

\(G=2.4.6+4.6.8+6.8.10+...+18.20.22\) ( xem lại đề có nhầm dấu ko nha bn ) 

\(8G=2.4.6.8+4.6.8.8+6.8.10.8+...+18.20.22.8\)

\(8G=2.4.6.8+4.6.8.\left(10-2\right)+6.8.10.\left(12-4\right)+...+18.20.22\left(24-16\right)\)

\(8G=2.4.6.8+4.6.8.10-2.4.6.8+6.8.10.12-4.6.8.10+...+18.20.22.24-16.18.20.22\)

\(8G=18.20.22.24\)

\(8G=190080\)

\(G=\frac{190080}{8}\)

\(G=23760\)

Chúc bạn học tốt ~ 

\(H=1.3.5+3.5.7+5.7.9+...+17.19.21\)

\(8H=1.3.5.8+3.5.7.8+5.7.9.8+...+17.19.21.8\)

\(8H=1.3.5.8+3.5.7.\left(9-1\right)+5.7.9.\left(11-3\right)+...+17.19.21.\left(23-15\right)\)

\(8H=1.3.5.8+3.5.7.9-1.3.5.7+5.7.9.11-3.5.7.9+...+17.19.21.23-15.17.19.21\)

\(8H=1.3.5.8-1.3.5.7+17.19.21.23\)

\(8H=15+156009\)

\(8H=156024\)

\(H=\frac{156024}{8}\)

\(H=19503\)

Chúc bạn học tốt ~ 

1) \(373737.73-37.737373\)

\(=37.10101.73-37.73.10101\)

\(=0\)

2) \(19.41414141-41.19191919\)

\(=19.41.1010101-41.19.1010101\)

\(=0\)

3) \(123456.456789456789-456789.123456123456\)

\(=123456.456789.1000001-456789.123456.1000001\)

\(=0\)

4) \(250.12.7\)

\(=250.4.3.7\)

\(=\left(250.4\right).\left(3.7\right)\)

\(=1000.21\)

\(=21000\)

5) \(24.125.9\)

\(=3.8.125.9\)

\(=\left(3.9\right).\left(8.125\right)\)

\(=27.1000\)

\(=27000\)

6) \(125.44.18\)

\(=125.4.11.2.9\)

\(=\left(125.4.2\right).\left(11.9\right)\)

\(=1000.99\)

\(=99000\)

7) \(8.24.6+12.4.52+2.22.24\)

\(=48.24+48.52+48.22\)

\(=48\left(24+52+22\right)\)

\(=48.98\)

\(=48\left(100-2\right)\)

\(=48.100-48.2\)

\(=4800-96\)

\(=4704\)

8) \(18.58.2-9.27.4+12.69.3\)

\(=36.58-36.27+36.69\)

\(=36\left(58-27+69\right)\)

\(=36.100=3600\)

9) \(30.85.3+18.72.5-45.37.2-9.20.10\)

\(=90.85+90.72-90.37-90.20\)

\(=90\left(85+72-37-20\right)\)

\(=90.100=9000\)

a) 4/9.x=25/18:2/3

4/9.x=25/18.3/2

4/9.x=75/36

x=75/36:4/9

x=75/36x4/9

x=675/144

b)x:4/5=25/8:5/4

x:4/5=25/8x4/5

x:4/5=100/40

x:4/5=5/2

x=5/2x4/5

x=20/10

x=2/1=2

c)22/5:x=44/5:5/2

22/5:x=44/5x2/5

22/5:x=88/25

x=88/25:22/5

x=88/25x22/5

x=440/550

x=4/5

h nk

so sánh hộ mình nhé

\(\dfrac{4}{9}=\dfrac{44}{99};\dfrac{5}{11}=\dfrac{45}{99};\dfrac{44}{99}< \dfrac{45}{99}\Rightarrow\dfrac{4}{9}< \dfrac{5}{11}\\ \dfrac{2}{3}=\dfrac{8}{12}< \dfrac{11}{2}\\ \dfrac{7}{18}>\dfrac{7}{24}\left(18< 24\right)\\ \dfrac{12}{13}=\dfrac{12\cdot101}{13\cdot101}=\dfrac{1212}{1313}>\dfrac{1010}{1313}\\ \dfrac{2}{5}=\dfrac{2\cdot11}{5\cdot11}=\dfrac{22}{55}\\ \dfrac{6}{7}< 1< \dfrac{7}{6}\)

2/3 + 3/4=17/12
9/4 + 3/5=57/20
5/24 + 1/4=11/24
3/15 - 5/35=2/35        18/27 - 2/6=1/3        37/12 - 3=1/12
11/9 x 3/22=1/6         7/13 x 13/7=1       4 x6/7=24/7
2/5 : 3/10=4/3           3/8 : 9/4=1/6            8/21 : 4/7=2/3

2/3 + 3/4

= 17/12
9/4 + 3/5

= 57/20
5/24 + 1/4

=11/24
3/15 - 5/35   

=2/35   

18/27 - 2/6   

=1/3   

37/12 - 3

= 1/12
11/9 x 3/22 

=1/6       

7/13 x 13/7 

=1   

 4 x6/7

=24/7
2/5 : 3/10

=4/3         

 3/8 : 9/4   

=1/6       

8/21 : 4/7

= 2/3

1=17/12
2=57/20
3=11/24
4=2/35        7=1/3        10=1/12
5=1/6         8=1       11=24/7

6=4/3           9=1/6            12=2/3

a)

\(2018-\left(\dfrac{3}{5}+\dfrac{3}{4}\right)-\left(\dfrac{2}{3}+2018-\dfrac{3}{5}\right)-\left|-1\right|\)

\(=2018-\dfrac{3}{5}-\dfrac{3}{4}-\dfrac{2}{3}-2018+\dfrac{3}{5}-1\)

\(=-\dfrac{3}{4}-\dfrac{2}{3}-1\)

\(=-\dfrac{2}{12}\)

Câu b) đề không rõ, nhìn rối lắm bạn! :)))

Câu c) không tính nhanh được, bạn tính trong ngoặc trước nha!

Chúc bạn học tốt!

a) \(\frac{9}{22}\cdot\frac{33}{8}=\frac{3^2\cdot3\cdot11}{2\cdot11\cdot2^3}=\frac{3^4}{2^4}=\frac{81}{16}\)

b) \(\frac{12}{35}:\frac{36}{35}=\frac{2^2\cdot3}{2^2\cdot3^2}=\frac{1}{3}\)

c) \(\frac{19}{17}:\frac{76}{51}=\frac{19\cdot3\cdot17}{17\cdot2^2\cdot19}=\frac{3}{4}\)

\(A=1+2+3+...+7+8=\dfrac{\left(8+1\right).\left(\dfrac{8-1}{1}+1\right)}{2}=36\)

\(B=3+4+5+...+10+11=\dfrac{\left(11+3\right).\left(\dfrac{11-3}{1}+1\right)}{2}=63\)

\(C=1+3+5+...+13+15=\dfrac{\left(15+1\right).\left(\dfrac{15-1}{2}+1\right)}{2}=64\)

\(D=2+4+6+...+18+20=\dfrac{\left(20+2\right).\left(\dfrac{20-2}{2}+1\right)}{2}=110\)

\(E=1+4+7+...+22+25=\dfrac{\left(25+1\right).\left(\dfrac{25-1}{3}+1\right)}{2}=117\)

\(G=1+5+9+...+33+37+41=\dfrac{\left(41+1\right).\left(\dfrac{41-1}{4}+1\right)}{2}=231\)