Hello?

a, 92x+92=9292

92x=9200

x=100

vậy...

b,892+x=928

x=36

vậy...

c,-192+x=921

x=1113

d,2030(x+829)=82937

x+829=82937/2030

x=82937/2030-829

e,7283-8x=3

8x=7280

x=910

f, 829-x=109

x=720

vậy ...........

tìm x 

a) 92x + 92 = 9292

92x = 9200

x = 9200 : 92

x = 100

   vậy x = 100

b) 892 + x = 928

x = 928 - 892

x = 36

    vậy x = 36

c) -192 + x = 921

x = 921 -(-192)

x = 1113

    vậy x = 1113

d) 2030 . ( x + 829 ) = 82937

x + 829 = 82937 : 2030

x + 829 = 82937/2030

x = 82937/2030 - 829 

x = .....

e) 7283 - 8x = 3

8x = 7283 - 3

8x = 7280 

x = 7280 : 8

x = 910

    vậy x = 910

f) 829 - x = 109

x = 829 - 109

x = 720

    vậy x = 720

k cho mk nha

Alô?

Các bn?

Bài này easy mà =v máy tiính đâu =3

a)100891

b)3648

c)2740608

d)9253

e)863287

f)1042351

g)18456

h)90130

i)221

j)7370049881

k)0

l)207359171

m)1609

n)2020

o)1029

p)102720

q)2220

r)10

s)89798979

t)-10

u)1000

v)1

w)11721

x)11749

y)9175403

z)-10

k cho mk nha,ấn mỏi tay r

\(a_{n-1}=\frac{1}{1+2+3+...+n}=\frac{2}{n\left(n+1\right)}\)=>\(1-a_{n-1}=1-\frac{2}{n\left(n+1\right)}=\frac{n\left(n+1\right)-2}{n\left(n+1\right)}=\frac{\left(n-1\right)\left(n+2\right)}{n\left(n+1\right)}\)

\(A=\left(1-\frac{2}{2.3}\right)\left(1-\frac{2}{3.4}\right)........\left(1-\frac{2}{2006.2007}\right)\)

\(=\left(\frac{1.4}{2.3}\right)\left(\frac{2.5}{3.4}\right)\left(\frac{3.6}{4.5}\right)........\left(\frac{2005.2008}{2006.2007}\right)\)\(=\frac{\left(1.2.3......2005\right)\left(4.5.6.....2008\right)}{\left(2.3.4.....2006\right)\left(3.4.5....2007\right)}=\frac{1.2008}{2006.3}=\frac{1004}{3009}\)

\(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2.2^9}\)

=\(\frac{\left(\frac{2}{5}.5\right)^7+\left(\frac{9}{4}:\frac{3}{16}\right)^3}{2^7.5^2.2^9}\)

=\(\frac{2^7+\left(\frac{9}{4}.\frac{16}{3}\right)^3}{2^7.5^2.2^9}\)

=\(\frac{2^7+3^3.4^3}{2^7.5^2.2^9}\)

=\(\frac{2^7+3^3.2^6}{2^7.5^2.2^9}\)

=\(\frac{2^6.\left(27+2\right)}{2^6.5^2.2^{10}}\)

=\(\frac{29}{25600}\)

Đoạn \(\frac{2^6\cdot\left(27+2\right)}{2^6\cdot5^2\cdot2^{10}}\)là sai rồi bn ơi!!!

Bn phải lm như mục trên là:

\(\frac{2^6\left(2+3^3\right)}{2^7\left(5^2+2^2\right)}\)\(=\frac{2^6\cdot29}{2^7\cdot29}=\frac{1}{2}\)

Nhưng dù sao cx c.ơn bn vì đã giúp mk,mk sẽ cho bn 1 ths nka!!!

a)

\(\left( { - 3,5} \right).\left( {1\frac{3}{5}} \right) = \frac{{ - 7}}{2}.\frac{8}{5} = \frac{{ - 7.8}}{{2.5}} = \frac{{ - 7.4.2}}{{2.5}} = \frac{{ - 28}}{5}\)                  

b) \(\frac{{ - 5}}{9}.\left( { - 2\frac{1}{2}} \right) = \frac{{ - 5}}{9}.\frac{{ - 5}}{2} = \frac{{25}}{{18}}\)

\(a)\frac{2}{{15}} + \left( {\frac{{ - 5}}{{24}}} \right) = \frac{{16}}{{120}} + \left( {\frac{{ - 25}}{{120}}} \right) = \frac{{ - 9}}{{120}} = \frac{{ - 3}}{{40}}\)          

 b) \(\left( {\frac{{ - 5}}{9}} \right) - \left( { - \frac{7}{{27}}} \right) = \left( {\frac{{ - 15}}{{27}}} \right) + \frac{7}{{27}} = \frac{{ - 8}}{{27}}\)          

 c)\(\left( { - \frac{7}{{12}}} \right) + 0,75 = \left( { - \frac{7}{{12}}} \right) + \frac{75}{100} \\= \left( { - \frac{7}{{12}}} \right) + \frac{3}{4} \\= \left( { - \frac{7}{{12}}} \right) + \frac{9}{{12}} = \frac{2}{{12}} = \frac{1}{6}\)

d)\(\left( {\frac{{ - 5}}{9}} \right) - 1,25 =\left( {\frac{{ - 5}}{9}} \right) - \frac{125}{100} = \left( {\frac{{ - 5}}{9}} \right) - \frac{5}{4}\\ = \left( {\frac{{ - 20}}{{36}}} \right) - \frac{{45}}{{36}} = \frac{{ - 65}}{{36}}\)       

 e)\(0,34.\frac{{ - 5}}{{17}} =\frac{{34}}{{100}}.\frac{{ - 5}}{{17}} = \frac{{17}}{{50}}.\frac{{ - 5}}{{17}} = \frac{{ - 1}}{{10}}\)                       

g) \(\frac{4}{9}:\left( { - \frac{8}{{15}}} \right) = \frac{4}{9}.\left( { - \frac{{15}}{8}} \right) = \frac{{ - 5}}{6}\)

h)\(\left( {1\frac{2}{3}} \right):\left( {2\frac{1}{2}} \right) = \frac{5}{3}:\frac{5}{2} = \frac{5}{3}.\frac{2}{5} = \frac{2}{3}\)       

i) \(\frac{2}{5}.\left( { - 1,25} \right) = \frac{2}{5}.\frac{{ - 125}}{100} = \frac{2}{5}.\frac{{ - 5}}{4} = \frac{{ - 1}}{2}\)                     

k) \(\left( {\frac{{ - 3}}{5}} \right).\left( {\frac{{15}}{{ - 7}}} \right).3\frac{1}{9} = \left( {\frac{{ - 3}}{5}} \right).\left( {\frac{{15}}{{ - 7}}} \right).\frac{{28}}{9}\\ = \frac{{ - 3.3.5.7.4}}{{5.\left( { - 7} \right).3.3}} = 4\)

\(\left[\left(\frac{2}{1001}-\frac{3}{2002}\right).\frac{1001}{17}+\frac{33}{34}\right]:\left[\left(\frac{7}{1008}+\frac{11}{2016}\right).\frac{1008}{25}+\frac{1009}{2016}\right]\)

\(=\left[\left(\frac{4}{2002}-\frac{3}{2002}\right).\frac{1001}{17}+\frac{33}{34}\right]:\left[\left(\frac{14}{2016}+\frac{11}{2016}\right).\frac{1008}{25}+\frac{1009}{2016}\right]\)

\(=\left(\frac{1}{2002}.\frac{1001}{17}+\frac{33}{34}\right):\left(\frac{25}{2016}.\frac{1008}{25}+\frac{1009}{2016}\right)\)

\(=\left(\frac{1}{34}+\frac{33}{34}\right):\left(\frac{1}{2}+\frac{1009}{2016}\right)\)

\(=1:\frac{2017}{2016}\)

\(=\frac{2016}{2017}\)

Câu này bạn có thể áp dụng phương pháp phân phối để rút gọn các phân số cho dễ nhé. Còn bạn cũng có thể áp dụng cách quy đồng cũng ko sai. Sorry bn nhé mình đang bận nên ko trình bày rõ đc ạ

\(\left[\left(\frac{2}{1001}-\frac{3}{2002}\right).\frac{1001}{17}+\frac{33}{34}\right]:\left[\left(\frac{7}{1008}+\frac{11}{2016}\right).\frac{1008}{25}+\frac{1009}{2016}\right]\)

\(=\left[\frac{1001}{17}.\frac{2}{1001}-\frac{3}{2002}.\frac{1001}{17}+\frac{33}{34}\right]:\left[\left(\frac{1008}{25}.\frac{7}{1008}+\frac{1008}{25}.\frac{11}{2016}+\frac{1009}{2016}\right)\right]\)

\(=\left[\frac{2}{17}-\frac{3}{34}+\frac{33}{34}\right]:\left[\frac{7}{25}+\frac{11}{50}+\frac{1009}{2016}\right]\)

\(=\left[\frac{2}{17}+\frac{15}{17}\right]:\left[\frac{14}{50}+\frac{11}{50}+\frac{1009}{2016}\right]\)

\(=1:\left[\frac{1}{2}+\frac{1009}{2016}\right]\)

\(=1:\left[\frac{1008}{2016}+\frac{1009}{2016}\right]\)

\(=1:\frac{2017}{2016}\)

\(=\frac{2016}{2017}\)

Học tốt nha!!!

a)

\(\begin{array}{l}A = \frac{5}{{11}}.\left( {\frac{{ - 3}}{{23}}} \right).\frac{{11}}{5}.\left( { - 4,6} \right)\\A = \frac{5}{{11}}.\left( {\frac{{ - 3}}{{23}}} \right).\frac{{11}}{5}.\frac{{ - 23}}{5}\\A = \frac{{5.\left( { - 3} \right).11.\left( { - 23} \right)}}{{11.23.5.5}}\\A = \frac{3}{5}\end{array}\)  

b)

\(\begin{array}{l}B = \left( {\frac{{ - 7}}{9}} \right).\frac{{13}}{{25}} - \frac{{13}}{{25}}.\frac{2}{9}\\B = \frac{{13}}{{25}}.\left( {\frac{{ - 7}}{9} - \frac{2}{9}} \right)\\B = \frac{{13}}{{25}}.(-1)\\B = \frac{{-13}}{{25}}.\end{array}\)