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8 tháng 5 2022

\(\dfrac{a}{b}=\dfrac{3}{5}:\dfrac{2}{7}\)

\(\dfrac{a}{b}=\dfrac{21}{10}\)

8 tháng 5 2022

\(\dfrac{a}{b}=\dfrac{3}{5}:\dfrac{2}{7}\)

\(\dfrac{a}{b}=\dfrac{3}{5}\times\dfrac{7}{2}=\dfrac{21}{10}\)

6 tháng 5 2022

a)\(\dfrac{a}{b}=5-\dfrac{3}{5}=\dfrac{25}{5}-\dfrac{3}{5}=\dfrac{22}{5}\)

b)\(\dfrac{a}{b}=\dfrac{5}{6}+\dfrac{4}{7}=\dfrac{35}{42}+\dfrac{24}{42}=\dfrac{59}{42}\)

c)\(\dfrac{a}{b}=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{3}{5}\times\dfrac{3}{2}=\dfrac{9}{10}\)

6 tháng 5 2022

d)\(\dfrac{a}{b}=3\times\dfrac{2}{7}=\dfrac{6}{7}\)

e)\(\dfrac{a}{b}=\dfrac{7}{5}-\left(\dfrac{2}{5}\times\dfrac{1}{2}\right)=\dfrac{7}{5}-\dfrac{1}{5}=\dfrac{6}{5}\)

1 tháng 7 2021

\(a,5x\dfrac{7}{3}=\dfrac{5}{1}x\dfrac{7}{3}=\dfrac{35}{3};b,\dfrac{13}{4}:7=\dfrac{13}{4} :\dfrac{7}{1}=\dfrac{13}{4}x\dfrac{1}{7}=\dfrac{13}{28}\)

1 tháng 7 2021

1. Tính 

\(a,5\times\dfrac{7}{3}=\dfrac{35}{3}\)

\(b,\dfrac{13}{4}:7=\dfrac{13}{4}\times\dfrac{1}{7}=\dfrac{13}{28}\)

2. Tính

\(a,\dfrac{3}{7}+\dfrac{2}{5}+\dfrac{3}{4}\)

\(=\dfrac{15}{35}+\dfrac{14}{35}+\dfrac{3}{4}\)

\(=\dfrac{29}{35}+\dfrac{3}{4}\)

\(=\dfrac{116}{140}+\dfrac{105}{140}\)

\(=\dfrac{221}{140}\)

\(b,\dfrac{9}{7}-\dfrac{5}{11}\times\dfrac{11}{7}\)

\(=\dfrac{9}{7}-\dfrac{55}{77}\)

\(=\dfrac{99}{77}-\dfrac{55}{77}\)

\(=\dfrac{44}{77}=\dfrac{4}{7}\)

\(c,\dfrac{3}{5}\times\dfrac{5}{7}+\dfrac{4}{7}\)

\(=\dfrac{3}{5}\times\left(\dfrac{5}{7}+\dfrac{4}{7}\right)\)

\(=\dfrac{3}{5}\times\dfrac{9}{7}\)

\(=\dfrac{27}{35}\)

\(d,\dfrac{7}{9}\times\dfrac{2}{5}:\dfrac{3}{11}\)

\(=\dfrac{14}{45}:\dfrac{3}{11}\)

\(=\dfrac{14}{45}\times\dfrac{11}{3}\)

\(=\dfrac{154}{135}\)

\(e,\dfrac{9}{7}+\dfrac{2}{3}-\dfrac{1}{4}\)

\(=\dfrac{27}{21}+\dfrac{14}{21}-\dfrac{1}{4}\)

\(=\dfrac{41}{21}-\dfrac{1}{4}\)

\(=\dfrac{164}{84}-\dfrac{21}{84}\)

\(=\dfrac{143}{84}\)

\(g,\dfrac{4}{9}:\dfrac{3}{5}\times\dfrac{2}{11}\)

\(=\dfrac{4}{9}\times\dfrac{5}{3}\times\dfrac{2}{11}\)

\(=\dfrac{20}{27}\times\dfrac{2}{11}\)

\(=\dfrac{40}{297}\)

\(h,\dfrac{7}{2}-\dfrac{3}{10}:\dfrac{2}{5}\)

\(=\left(\dfrac{7}{2}-\dfrac{3}{10}\right):\dfrac{2}{5}\)

\(=\left(\dfrac{35}{10}-\dfrac{3}{10}\right):\dfrac{2}{5}\)

\(=\dfrac{32}{10}:\dfrac{2}{5}\)

\(=\dfrac{16}{5}\times\dfrac{5}{2}\)

\(=\dfrac{80}{10}=8\)

8 tháng 5 2022

bài 1

a)\(=\dfrac{16}{40}+\dfrac{15}{40}=\dfrac{31}{40}\)

b)\(=\dfrac{7}{6}-\dfrac{4}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)

c)\(=\dfrac{30}{9}=\dfrac{10}{3}\)

d)\(=\dfrac{8}{5}\times\dfrac{7}{4}=\dfrac{56}{20}=\dfrac{14}{5}\)

8 tháng 5 2022

bài 2

a)\(x=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)

b)\(x=5\times\dfrac{10}{7}=\dfrac{50}{7}\)

bài 4 :

145 ×× 69 + 22 x  145 +145 x 8 + 145 

\(=145\times\left(69+22+8+1\right)=145\times100=14500\)

 

15 tháng 8 2023

\(a,A=\dfrac{\dfrac{5}{4}+\dfrac{5}{5}+\dfrac{5}{7}-\dfrac{5}{11}}{\dfrac{10}{4}+\dfrac{10}{5}+\dfrac{10}{7}-\dfrac{10}{11}}\\ =\dfrac{5.\left(\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{11}\right)}{10.\left(\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{11}\right)}\\ =\dfrac{5}{10}\\ =\dfrac{1}{2}\)

Vậy \(A=\dfrac{1}{2}\)

\(b,B=\dfrac{2+\dfrac{6}{5}-\dfrac{6}{7}-\dfrac{6}{11}}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\\ =\dfrac{3.\left(\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}\right)}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\\ =3\)

Vậy \(B=3\)

27 tháng 8 2023

a, - \(\dfrac{2}{5}\) + \(\dfrac{4}{5}\).\(x\) = \(\dfrac{3}{5}\)

               \(\dfrac{4}{5}\).\(x\) = \(\dfrac{3}{5}\)\(\dfrac{2}{5}\)

                 \(\dfrac{4}{5}\).\(x\) = 1

                      \(x\) = \(\dfrac{5}{4}\)

b, - \(\dfrac{3}{7}\) - \(\dfrac{4}{7}\)\(x\) = \(\dfrac{2}{5}\)

              \(\dfrac{4}{7}\)\(x\) = - \(\dfrac{3}{7}\) - \(\dfrac{2}{5}\)

                \(\dfrac{4}{7}\)\(x\) = - \(\dfrac{29}{35}\)

                  \(x\) = \(\dfrac{4}{7}\): (- \(\dfrac{29}{35}\) )

                  \(x\) = - \(\dfrac{20}{29}\)

27 tháng 8 2023

c, \(\dfrac{4}{7}\).\(x\) + \(\dfrac{2}{3}\) = - \(\dfrac{1}{5}\)

     \(\dfrac{4}{7}\).\(x\)         = -\(\dfrac{1}{5}\) - \(\dfrac{2}{3}\)

      \(\dfrac{4}{7}\).\(x\)       = - \(\dfrac{13}{15}\)

           \(x\)     = - \(\dfrac{13}{15}\)\(\dfrac{4}{7}\)

            \(x\)    = - \(\dfrac{91}{60}\)

14 tháng 5 2021

\(a.\dfrac{2}{3}+\dfrac{4}{3}:\dfrac{-2}{3}=\dfrac{2}{3}+\left(-2\right)=\dfrac{-4}{3}\)

\(b.3\dfrac{4}{5}-\left(2\dfrac{1}{4}+1\dfrac{4}{5}\right)\\ =3\dfrac{4}{5}-2\dfrac{1}{4}-1\dfrac{4}{5}\\ =\left(3\dfrac{4}{5}-1\dfrac{4}{5}\right)-2\dfrac{1}{4}\\ =2-2\dfrac{1}{4}=\dfrac{1}{4}\)

\(c.\dfrac{-3}{5}.\dfrac{4}{7}+\dfrac{3}{7}.\dfrac{-3}{5}+\dfrac{3}{5}\\ =\dfrac{-3}{5}\left(\dfrac{4}{7}+\dfrac{3}{7}\right)+\dfrac{3}{5}\\ =\dfrac{-3}{5}+\dfrac{3}{5}=0\)

14 tháng 5 2021

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

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

\(=\dfrac{2}{5}+-2\)

\(=\dfrac{2}{5}+\dfrac{-10}{5}\)

\(=\dfrac{-8}{5}\)

15 tháng 11 2021

\(a,=\dfrac{5}{7}-\dfrac{33}{8}=-\dfrac{191}{56}\\ b,=\left(\dfrac{12}{17}+\dfrac{5}{17}\right)+\left(\dfrac{19}{7}+\dfrac{3}{7}\right)=1+3=4\\ c,=\left(0,125\cdot8\right)^{12}-\left(\dfrac{45}{15}\right)^3=1-3^3=-26\\ d,=\left(-\dfrac{1}{3}\right)\left(5\dfrac{2}{7}-2\dfrac{2}{7}\right)=-\dfrac{1}{3}\cdot3=-1\\ e,=\dfrac{3^4\cdot3^6}{3^9}=3\)

15 tháng 11 2021

Thank you ^^

22 tháng 6 2022

a) A=[27(14−13)]:[27(13−25)]=(14−13):(13−25)=114.
b) B=34(15−27−13+27)15(27+13)−13(27+13)=34(15−13)(15−13)(27+13)=11152.

13 tháng 7 2022

a) \mathrm{A}=\left[\dfrac{2}{7}\left(\dfrac{1}{4}-\dfrac{1}{3}\right)\right]:\left[\dfrac{2}{7}\left(\dfrac{1}{3}-\dfrac{2}{5}\right)\right]=\left(\dfrac{1}{4}-\dfrac{1}{3}\right):\left(\dfrac{1}{3}-\dfrac{2}{5}\right)=1 \dfrac{1}{4}.
b) \mathrm{B}=\dfrac{\dfrac{3}{4}\left(\dfrac{1}{5}-\dfrac{2}{7}-\dfrac{1}{3}+\dfrac{2}{7}\right)}{\dfrac{1}{5}\left(\dfrac{2}{7}+\dfrac{1}{3}\right)-\dfrac{1}{3}\left(\dfrac{2}{7}+\dfrac{1}{3}\right)}=\dfrac{\dfrac{3}{4}\left(\dfrac{1}{5}-\dfrac{1}{3}\right)}{\left(\dfrac{1}{5}-\dfrac{1}{3}\right)\left(\dfrac{2}{7}+\dfrac{1}{3}\right)}=1 \dfrac{11}{52}

17 tháng 4 2023

cậu lấy máy tính,tính đi ạ

 

26 tháng 12 2023

a) 2/3 + 3/4 . (-4/9)

= 2/3 - 1/3

= 1/3

b) -5/7 . 31/33 + (-5/7) : 33/2

= -5/7 . 31/33 - 5/7 . 2/33

= -5/7 . (31/33 + 2/33)

= -5/7 . 1

= -5/7

c) -3/5 . 13/11 - (-3/5) . 2/11

= -3/5 . (13/11 - 2/11)

= -3/5 . 1

= -3/5