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4 tháng 1 2018

7/3:0,2X=7/6:0,8

35/3X=35/24

X=35/24:35/3

X=1/8

4 tháng 1 2018

7/3 : 0,2x = 7/6 : 0,8

7/3 : 0,2x = 35/24

        0,2x = 7/3 : 35/24

        0,2x = 8/5

             x = 8/5 : 0,2

             x = 8

4 tháng 1 2018

7/3:0.2x=7/6:0.8

7/3 : 0.2 x = 35/24

0.2 x = 35/24 : 7/3

0.2 x = 5/8

x=5/8 : 0.2

x= 25/8

Vậy x=25/8

4 tháng 1 2018

=>\(\dfrac{7}{3}:0,2x=\dfrac{7}{6}.\dfrac{5}{4}\)

=>\(\dfrac{7}{3}:0,2x=\dfrac{35}{24}\)

=>0,2\(.x=\dfrac{7}{3}:\dfrac{35}{24}\)

=>0,2\(.x=\dfrac{7}{3}.\dfrac{24}{35}\)

=>0,2.\(x=\dfrac{8}{5}\)

=>\(x=\dfrac{8}{5}:0,2\)

=>\(x=\dfrac{8}{5}.5\)

=>\(x=8\)

Vậy x=8

4 tháng 1 2018

\(\dfrac{7}{3}:0,2x=\dfrac{7}{6}:0,8\)

\(\dfrac{7}{3}:0,2x=\dfrac{35}{24}\)

\(0,2x=\dfrac{7}{3}:\dfrac{35}{24}\)

\(0,2x=1,6\)

⇔ x = 1,6 : 0,2

⇔ x = 8

Vậy x =8

tính a) \(\left[\dfrac{0.8\div\left(\dfrac{4}{5}\cdot1025\right)}{0.64-1}+\dfrac{\left(1.08-\dfrac{2}{25}\right)\div\dfrac{4}{7}}{\left(6\dfrac{5}{7}-3\dfrac{1}{4}\right)\cdot2\dfrac{2}{17}}+\left(1.2\cdot0.5\right)\div\dfrac{4}{5}\right]\) b) \(\left(0.2\right)^{-3}\left[\left(-\dfrac{1}{5}\right)^{-2}\right]^{-1}+\left[\left(\dfrac{1}{2}\right)^{-3}\right]^{-2}\div\left(2^{-3}\right)^{-1}-\left(0.175\right)^{-2}\) c) \(2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{1+\dfrac{1}{2}}}}\) d)...
Đọc tiếp

tính

a) \(\left[\dfrac{0.8\div\left(\dfrac{4}{5}\cdot1025\right)}{0.64-1}+\dfrac{\left(1.08-\dfrac{2}{25}\right)\div\dfrac{4}{7}}{\left(6\dfrac{5}{7}-3\dfrac{1}{4}\right)\cdot2\dfrac{2}{17}}+\left(1.2\cdot0.5\right)\div\dfrac{4}{5}\right]\)

b) \(\left(0.2\right)^{-3}\left[\left(-\dfrac{1}{5}\right)^{-2}\right]^{-1}+\left[\left(\dfrac{1}{2}\right)^{-3}\right]^{-2}\div\left(2^{-3}\right)^{-1}-\left(0.175\right)^{-2}\)

c) \(2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{1+\dfrac{1}{2}}}}\)

d) \(\dfrac{1}{90}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{3}\)

e) \(\left(\dfrac{1}{3}\right)^{-1}-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2\div2\)

f) \(\dfrac{\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{13}}{\dfrac{2}{3}-\dfrac{2}{7}-\dfrac{2}{13}}\cdot\dfrac{\dfrac{3}{4}-\dfrac{3}{16}-\dfrac{3}{64}-\dfrac{3}{256}}{1-\dfrac{1}{4}-\dfrac{1}{16}-\dfrac{1}{64}}+\dfrac{5}{8}\)

g) \(\dfrac{1}{-\left(2017\right)\left(-2015\right)}+\dfrac{1}{\left(-2015\right)\left(-2013\right)}+...+\dfrac{1}{\left(-3\right)\cdot\left(-1\right)}\)

h) \(\left(1-\dfrac{1}{1\cdot2}\right)+\left(1-\dfrac{1}{2\cdot3}+...+\left(1-\dfrac{1}{2017\cdot2018}\right)\right)\)

3
7 tháng 10 2017

c)

Ta có :\(2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{1+\dfrac{1}{2}}}}\)

\(=2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{\dfrac{3}{2}}}}\) \(=2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{2}{3}}}\) \(=2+\dfrac{1}{1+\dfrac{1}{\dfrac{8}{3}}}\) \(=2+\dfrac{1}{1+\dfrac{3}{8}}\) \(=2+\dfrac{1}{\dfrac{11}{8}}\) \(=2+\dfrac{8}{11}\) \(=\dfrac{30}{11}\)

7 tháng 10 2017

d) \(\left(\dfrac{1}{3}\right)^{-1}-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2\)

\(=3-1+\left(\dfrac{1}{2}\right)^2:2\)

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

\(=3-1+\dfrac{1}{8}\)

\(=\dfrac{17}{8}\)

a: \(=6+\dfrac{4}{5}-1-\dfrac{2}{3}-3-\dfrac{4}{5}\)

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

b: \(=7+\dfrac{5}{9}-2-\dfrac{3}{4}-3-\dfrac{5}{9}=2-\dfrac{3}{4}=\dfrac{5}{4}\)

c: =6+7/7-1-3/4-2-5/7

=3+2/7-3/4

=84/28+8/28-21/28

=84/28-13/28

=71/28

28 tháng 9 2018

Đây là tính hợp lí ... mà câu a là 27,5 chứ không phải 2,75...

\(A=\dfrac{7,5-0,6+\dfrac{3}{7}+\dfrac{3}{13}}{27,5-2,2+\dfrac{11}{7}+\dfrac{11}{3}}=\dfrac{\dfrac{15}{2}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{13}}{\dfrac{55}{2}-\dfrac{11}{5}+\dfrac{11}{7}+\dfrac{11}{3}}\\ =\dfrac{3\left(\dfrac{5}{2}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{13}\right)}{11\left(\dfrac{5}{2}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{13}\right)}=\dfrac{3}{11}\)

b: \(=26:\left[\dfrac{3:0.1}{2.5\cdot2}+\dfrac{0.25\cdot4}{2}\right]+\dfrac{2}{3}\cdot\dfrac{21}{4}\)

\(=26:\left[\dfrac{30}{5}+1\right]+\dfrac{42}{12}\)

\(=\dfrac{26}{7}+\dfrac{42}{12}=\dfrac{101}{14}\)

c: \(=\left[\dfrac{4-3}{386}\cdot\dfrac{193}{17}+\dfrac{33}{34}\right]:\left[\dfrac{25}{4002}\cdot\dfrac{2001}{25}+\dfrac{9}{2}\right]\)

\(=\dfrac{\left(\dfrac{1}{34}+\dfrac{33}{34}\right)}{\dfrac{1}{2}+\dfrac{9}{2}}=1:5=\dfrac{1}{5}\)

9 tháng 9 2018

14\(\dfrac{6}{7}\) : \(\left(\dfrac{4}{3}-\dfrac{5}{7}\right)\) + \(14\dfrac{6}{7}\) : \(\left(\dfrac{2}{3}-\dfrac{2}{7}\right)\)

= 14\(\dfrac{6}{7}\) : \(\dfrac{13}{21}\) + 14\(\dfrac{6}{7}\) : \(\dfrac{8}{21}\)

= 14\(\dfrac{6}{7}\) :\(\left(\dfrac{13}{21}+\dfrac{8}{21}\right)\)

= 14\(\dfrac{6}{7}\) : 1

= \(\dfrac{104}{7}\)

9 tháng 9 2018

\(14\dfrac{6}{7}:\left(\dfrac{4}{3}-\dfrac{5}{7}\right)+14\dfrac{6}{7}:\left(\dfrac{2}{3}-\dfrac{2}{7}\right)\)

=\(14\dfrac{6}{7}:\left(\dfrac{13}{21}\right)+14\dfrac{6}{7}:\left(\dfrac{8}{21}\right)\)

=\(14\dfrac{6}{7}:\left(\dfrac{13}{21}+\dfrac{8}{21}\right)\)

=\(14\dfrac{6}{7}:1\)

=\(14\dfrac{6}{7}=\dfrac{104}{7}\)

\(A=\dfrac{\dfrac{3}{11}+\dfrac{3}{3}-\dfrac{3}{7}}{\dfrac{9}{11}+\dfrac{9}{3}-\dfrac{9}{7}}-\dfrac{\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{8}}{\dfrac{7}{6}+\dfrac{7}{8}-\dfrac{7}{10}+\dfrac{7}{16}}\)

\(=\dfrac{1}{3}-1:\dfrac{7}{2}=\dfrac{1}{3}-\dfrac{2}{7}=\dfrac{1}{21}\)

25 tháng 10 2021

\(1\)/

\(a\)\(=\left(\dfrac{7}{5}-\dfrac{8}{7}\right)+\dfrac{17}{5}:0,6\)

\(=\dfrac{9}{35}+\dfrac{17}{3}\)

\(=\dfrac{622}{105}\)

\(b\)\(=\dfrac{11}{6}+\dfrac{-14}{15}\)

\(=\dfrac{9}{10}\)

\(c\)\(=\dfrac{7}{4}-\dfrac{2}{3}\)

\(=\dfrac{13}{12}\)