K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

9 tháng 4 2018

\(2\frac{x}{7}=\frac{75}{35}\)

\(\frac{2.7+x}{7}=\frac{75}{35}\)

\(\frac{14+x}{7}=\frac{75}{35}\)

\(\frac{5\left(14+x\right)}{35}=\frac{75}{35}\)

=>5 ( 14 + x ) = 75

          14 + x   = 75 : 5

          14 + x   = 15

                  x    = 15 - 14

                  x   = 1

Vậy x =1

\(a,2\frac{x}{7}=\frac{75}{35}\)

\(\frac{75}{35}=2\frac{5}{35}=2\frac{1}{7}\)

\(\Rightarrow x=1\)

\(b,47:4=...\left(+3\right)\)

     \(\Rightarrow\left(47-3\right):4=11\)

      \(\Rightarrow x=11\)

\(c,\frac{112}{5}=\frac{336}{15}=22\left(+6\right)\)

     \(\Rightarrow x=22\frac{x=6}{15}\)

\(d,7,5x=\frac{75x}{100}:\left(9-6\frac{13}{21}\right)=2\frac{13}{25}\)

     \(\frac{75x}{100}:\left(9-\frac{139}{21}\right)=\frac{63}{25}\)

       \(\frac{75x}{100}:\frac{50}{21}=\frac{63}{25}\)

           \(\Rightarrow\frac{63^3}{25^{\left(1\right)}}\cdot\frac{50^{\left(2\right)}}{21^1}=6=\frac{6}{1}\)

             \(\Rightarrow\frac{6}{1}=\frac{600}{100}\)

Con d sai đề

21 tháng 8 2016

\(a,4\frac{3}{x}=\frac{47}{x}\)

\(\frac{4x+3}{x}=\frac{47}{x}\)

\(\Rightarrow4x^2+3x=47x\)

\(4x^2=47x-3x=44x\)

\(4x^2:4x=44x:4x\)

\(x=11\)

\(b,x\frac{x}{15}=\frac{112}{5}\)

\(\frac{15x+x}{15}=\frac{112}{5}\)

\(75x+5x=112.15\)

\(80x=1680\)

\(x=21\)

11 tháng 6 2017

a,        \(4\frac{3}{x}=\frac{47}{x}\)

   \(\Leftrightarrow\frac{4x+3}{x}=\frac{47}{x}\)

\(\Leftrightarrow4x+3=47\)

                \(4x=47-3\)

                \(4x=44\)

                  \(x=44:4\)

                  \(x=11\)

b,            \(x\frac{x}{15}=\frac{112}{5}\)

\(\Leftrightarrow\frac{15x+x}{15}=\frac{112}{5}\)

        \(\Leftrightarrow\frac{16x}{15}=\frac{336}{15}\)

          \(\Leftrightarrow16x=336\)

                       \(x=336:16\)

                       \(x=21\) 

18 tháng 11 2018

\(\frac{6}{11}x=\frac{9}{2}y=\frac{18}{5}z\Rightarrow\frac{6x}{11.18}=\frac{9y}{2.18}=\frac{18z}{5.18}\)

\(\Rightarrow\frac{-x}{-33}=\frac{y}{4}=\frac{z}{5}=\frac{-x+y+z}{-33+4+5}=\frac{-120}{-24}=5\)

\(\Rightarrow x=165;y=20;z=25\)

17 tháng 7 2016

a, \(\frac{1}{6}x+\frac{1}{10}-\frac{4}{15}x+1=0\)

\(\Leftrightarrow-\frac{1}{10}x=-\frac{11}{10}\)

\(\Leftrightarrow x=11\)

b,\(\left(\frac{1}{7}x-\frac{2}{7}\right)\left(-\frac{1}{5}x+\frac{3}{5}\right)\left(\frac{1}{3}x+\frac{4}{3}\right)=0\)

\(\Leftrightarrow\frac{1}{7}x-\frac{2}{7}=0\)hoặc \(-\frac{1}{5}x+\frac{3}{5}=0\)hoặc \(\frac{1}{3}x+\frac{4}{3}=0\)

+) \(\frac{1}{7}x-\frac{2}{7}=0\Leftrightarrow\frac{1}{7}x=\frac{2}{7}\Leftrightarrow x=2\)

+)\(-\frac{1}{5}x+\frac{3}{5}=0\Leftrightarrow-\frac{1}{5}x=-\frac{3}{5}\Leftrightarrow x=3\)

+)\(\frac{1}{3}x+\frac{4}{3}=0\Leftrightarrow\frac{1}{3}x=-\frac{4}{3}\Leftrightarrow x=-4\)

  c, \(\frac{1}{2}x-\frac{11}{15}:\frac{33}{35}=-\frac{1}{3}\)

\(\Leftrightarrow\frac{1}{2}x-\frac{7}{9}=-\frac{1}{3}\)

\(\Leftrightarrow\frac{1}{2}x=\frac{4}{9}\)

\(\Leftrightarrow x=\frac{8}{9}\)

17 tháng 7 2016

a/ \(\frac{1}{6}x+\frac{1}{10}-\frac{4}{15}x+1=0\)

    \(\Rightarrow-\frac{1}{10}x=-\frac{11}{10}\)

     \(\Rightarrow x=11\)

b/ \(\left(\frac{1}{7}x-\frac{2}{7}\right)\left(-\frac{1}{5}x+\frac{3}{5}\right)\left(\frac{1}{3}x+\frac{4}{3}\right)=0\)

   \(\Rightarrow\frac{1}{7}x-\frac{2}{7}=0\Rightarrow\frac{1}{7}x=\frac{2}{7}\Rightarrow x=2\)

hoặc \(-\frac{1}{5}x+\frac{3}{5}=0\Rightarrow-\frac{1}{5}x=-\frac{3}{5}\Rightarrow x=3\)

hoặc \(\frac{1}{3}x+\frac{4}{3}=0\Rightarrow\frac{1}{3}x=-\frac{4}{3}\Rightarrow x=-4\)

                                              Vậy x = 2, x = 3, x = -4

c/ \(\frac{1}{2}x-\frac{11}{15}:\frac{33}{35}=-\frac{1}{3}\)

     \(\Rightarrow\frac{1}{2}x-\frac{7}{9}=-\frac{1}{3}\)

      \(\Rightarrow\frac{1}{2}x=\frac{4}{9}\Rightarrow x=\frac{8}{9}\)

                                                                       Vậy x = 8/9

7 tháng 4 2018

a) \(4\frac{3}{x}=\frac{47}{x}\)

\(\Rightarrow\frac{4\times x+3}{x}=\frac{47}{x}\)

\(\Rightarrow4\times x+3=47\)

\(4\times x=47-3\)

\(4\times x=44\)

\(x=44:4=11\)

b) \(x\frac{x}{15}=\frac{112}{5}\)

\(\Rightarrow\frac{x\times15+x}{15}=\frac{336}{15}\)

\(\Rightarrow\frac{x\times16}{15}=\frac{336}{15}\)

\(\Rightarrow x\times16=336\)

\(x=21\)

Chúc bn học tốt!!!!

21 tháng 2 2018

\(\frac{1+0,6-\frac{3}{7}}{\frac{8}{3}+\frac{8}{5}-\frac{8}{7}}=\frac{\frac{3}{3}+\frac{3}{5}-\frac{3}{7}}{\frac{8}{3}+\frac{8}{5}-\frac{8}{7}}=\frac{3.\left(\frac{1}{3}+\frac{1}{5}-\frac{1}{7}\right)}{8.\left(\frac{1}{3}+\frac{1}{5}-\frac{1}{7}\right)}=\frac{3.1}{8.1}=\frac{3}{8}\)

\(\frac{\frac{1}{3}+0,25-\frac{1}{5}+0,125}{\frac{7}{6}+\frac{7}{8}-0,7+\frac{7}{16}}=\frac{\frac{1}{3}+\frac{1}{4}-\frac{1}{5}+\frac{1}{8}}{\frac{7}{6}+\frac{7}{8}-\frac{7}{10}+\frac{7}{16}}=\frac{1.\left(\frac{1}{3}+\frac{1}{4}-\frac{1}{5}+\frac{1}{8}\right)}{7.\left(\frac{1}{3}+\frac{1}{4}-\frac{1}{5}+\frac{1}{8}\right)}=\frac{1.1}{7.1}=\frac{1}{7}\)

=>\(\frac{3}{8}-\frac{1}{7}=\frac{13}{56}\)

21 tháng 2 2018

Mk đg cần gấp các bn giúp mk nha

12 tháng 2 2018

xin các bạn đấy giúp mk đi xin các bạn mà

19 tháng 2 2017

a/ \(\frac{2}{3}+\frac{4}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)

\(\Rightarrow\frac{82}{105}< \frac{x}{105}< \frac{92}{105}\)

\(\Rightarrow82< x< 92\)

\(\Rightarrow x=\left\{83;84;85;86;87;88;89;90;91\right\}\)

b/ \(-\frac{7}{15}+\frac{8}{60}+\frac{24}{90}\le\frac{x}{15}\le\frac{3}{5}+\frac{8}{30}+-\frac{4}{10}\)

\(\Rightarrow-\frac{1}{15}\le\frac{x}{15}\le\frac{7}{15}\)

\(\Rightarrow-1\le x\le7\)

\(\Rightarrow x=\left\{-1;0;1;2;3;4;5;6;7\right\}\)