10.6 : x + 7.19 : x = 3

(10,6+7,19):x=3

17,79:x=3

x=17,79:3

x=5,93

7 : x - 3.9 : x = 5

(7-3,9):x=5

3,1:x=5

x=3,1:5

x=0,62

\(a,10,6:x+7,19:x=3\\ \left(10,6+7,19\right):x=3\\ 17,79:x=3\\ x=17,79:3\\ x=5,93\\ b,7:x-3,9:x=5\\ \left(7-3,9\right):x=5\\ 3,1:x=5\\ x=3,1:5\\ x=0,62\)

\(10,6:x+7,19:x=3\)
\(\left(10,6+7,19\right):x=3\)
\(17,79:x=3\)
\(x=\dfrac{17,19}{3}\)
\(x=5,73\)
\(------------\)
\(7:x-3,9:x=5\)
\(\left(7-3,9\right):x=5\)
\(3,1:x=5\)
\(x=\dfrac{3,1}{5}\)
\(x=0,62\)

Tìm x chứ gì :

        X * 2,6 + X * 6,4 + X = 10,6

        X * [ 2,6 + 6,4 + 1 ] = 10,6

        X * 10 = 10,6

        X = 10,6 : 10 

        X = 1,06

                NHỚ K MÌNH NHÉ !!!!!!!!!!

a: \(=\dfrac{3}{7}\cdot\dfrac{7}{5}=\dfrac{3}{5}\)

b: \(=\dfrac{1}{5}+\dfrac{1}{9}=\dfrac{14}{45}\)

Giải cụ thể giúp mk nhé

Ta có: 2¹⁰.6¹⁵+3¹⁴.15.4¹³:2¹⁹ .18⁷.3-3¹⁵.2²⁵

          =2¹⁰.2¹⁵.3¹⁵+3¹⁴.3.5.2²⁶:2¹⁹.9⁷.2⁷.3-3¹⁵.2²⁵

        =2²⁵.3¹⁵+3¹⁵.2²⁵.10:2²⁵.3¹⁵.2-3¹⁵.2²⁵

          =2²⁵.3¹⁵+5-2²⁵.3¹⁵

        =5 

\(\frac{7}{4}-\left(\frac{1}{2.2}+\frac{1}{4.3}+\frac{1}{6.4}+\frac{1}{8.5}+\frac{1}{10.6}+\frac{1}{12.7}+\frac{1}{14.8}\right)\div x=0\)

\((\frac{1}{2.2}+\frac{1}{4.3}+\frac{1}{6.4}+\frac{1}{8.5}+\frac{1}{10.6}+\frac{1}{12.7}+\frac{1}{14.8})\div x=\frac{7}{4}\)

\((\frac{1}{4}+\frac{1}{12}+\frac{1}{24}+\frac{1}{40}+\frac{1}{60}+\frac{1}{84}+\frac{1}{112})\div x=\frac{7}{4}\)

\(\left[\frac{1}{2}\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}\right)\right]\div x=\frac{7}{4}\)

\(\left[\frac{1}{2}\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}\right)\right]\div x=\frac{7}{4}\)

\(\left[\frac{1}{2}\left(1-\frac{1}{8}\right)\right]\div x=\frac{7}{4}\)

\(\left(\frac{1}{2}.\frac{7}{8}\right)\div x=\frac{7}{4}\)

\(\frac{7}{16}\div x=\frac{7}{4}\)

\(x=\frac{7}{16}\div\frac{7}{4}\)

\(x=\frac{7}{16}\times\frac{4}{7}\)

\(x=\frac{1}{4}\)

\(\frac{7}{4}-\left(\frac{1}{2\cdot2}+\frac{1}{4\cdot3}+\frac{1}{6\cdot4}+\frac{1}{8\cdot5}+\frac{1}{10\cdot6}+\frac{1}{12\cdot7}+\frac{1}{14\cdot8}\right)\)

\(=\frac{7}{4}-\left(\frac{1}{4}+\frac{1}{12}+\frac{1}{24}+\frac{1}{40}+\frac{1}{60}+\frac{1}{84}+\frac{1}{112}\right)\)

\(=\frac{7}{4}-\frac{1}{2}\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}\right)\)

\(=\frac{7}{4}-\frac{1}{2}\left(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+\frac{1}{5\cdot6}+\frac{1}{6\cdot7}+\frac{1}{7\cdot8}\right)\)

\(=\frac{7}{4}-\frac{1}{2}\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}\right)\)

\(=\frac{7}{4}-\frac{1}{2}\left(1-\frac{1}{8}\right)\)

\(=\frac{7}{4}-\frac{1}{2}\cdot\frac{7}{8}\)

\(=\frac{7}{4}-\frac{7}{16}=\frac{28}{16}-\frac{7}{16}=\frac{21}{16}\)

chết mọe

lm lộn đề r

\(19\times5+7\times19+12-18\times12\)

\(=19\left(5+7\right)+12\left(1-18\right)\)

\(=19\times12+12\times\left(-17\right)\)

\(=12\left[19+\left(-17\right)\right]\)

\(=12\times2=24\)

19.5+7.19+12-18.12=19(5+7) +12(1-18)

                                =19.12+12(-17)

                                 =12(19-17)

                                   =12.2=24

19.5+17.19+12-18.12

=[ 19×(5+7)] + 12-216

=19.12+12-216

=288+(-204)

=24