(5 \(\times\) 13 - 45) \(\times\) \(x\) - 47 = 13

(65 - 45) \(\times\) \(x\)                = 13 + 47

20 \(\times\) \(x\)                         = 60

         \(x\)                         = 60 : 20

          \(x\)                        = 3

\(\Leftrightarrow\left(65-45\right)x-47=13\)
\(\Leftrightarrow20x=13+47=60\)
\(\Leftrightarrow x=3\)
Vậy \(x=3\) 

( 5 x 13 - 45 ) x X = 13 + 47

( 5 x 13 - 45 ) x X = 60

20 x X = 60

X = 60 : 20 

X = 3

Vậy x = 3

    -5 + (-37 - 45 + 51) - (-37 + 51)

=  -5  - 37 - 45 + 51 + 37 - 51

=  - (5 + 45) - (37 - 37) + (51 - 51)

= - 50 - 0 + 0

= - 50

  - (15 - 47 + 58) + (15 - 47 ) + 3

= - 15 + 47 - 58 + 15 - 47 + 3

= (-15 + 15) + (47 - 47) - (58 - 3)

= 0 + 0 - 55

= - 55

  (53 - 45 - 49) - (53 + 45 - 49)

= 53 -  45 - 49 - 53 - 45 + 49

= (53 - 53) + (-49 + 49) - (45 + 45)

= 0 + 0 - 90

= - 90 

    13 - 15 + 49 - 13 + 15 - 48

=  (13 - 13) + (-15 + 15) + (49 - 48)

= 0 + 0 + 1

=  1 

15+13 -15-13 +49-48

\(A=\left(\frac{3}{5}+\frac{47}{13}-\frac{25}{8}+\frac{1}{8}-\frac{8}{13}+\frac{2}{5}\right)\times\frac{2014}{2015}\)

\(A=\left[\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{47}{13}-\frac{8}{13}\right)-\left(\frac{25}{8}-\frac{1}{8}\right)\right]\times\frac{2014}{2015}\)

\(A=\left[1+3-3\right]\times\frac{2014}{2015}\)

\(A=1\times\frac{2014}{2015}\)

\(A=\frac{2014}{2015}\)

3/5+47/13-25/8+1/8-8/13+2/5 = 1 nhé!

     =>( \(\frac{3}{5}\)+ \(\frac{2}{5}\)) +  (\(\frac{47}{13}\)- \(\frac{8}{13}\)) - (\(\frac{25}{8}\)+ \(\frac{1}{8}\))

       => 1 + 3 - \(\frac{26}{8}\)

      => 4 - \(\frac{26}{8}\)

      => \(\frac{4}{1}\)- \(\frac{26}{8}\)

      => \(\frac{32-26}{8}\)

      => \(\frac{6}{8}\)

      => \(\frac{3}{4}\)

\(47\times\left(53-37\right)-53\times\left(47-37\right)\)

\(=47\times53-47\times37-53\times47+53\times37\)

\(=\left(47\times53-53\times47\right)+\left(53\times37-47\times37\right)\)

\(=0+\left(53-47\right)\times36=6\times36\)

\(=216\)

a=10

b=222

c=133056

d=0

\(2019.2016-1009-1000-2019.2015\)

\(=\left(2019.2016-2019.2015\right)-1009-1000\)

\(=2019-1009-1000\)

\(=1010-1000\)

\(=10\)

\(47.\left(53-37\right)-53.\left(47-37\right)\)

\(=47.53-47.37-53.47+53.37\)

\(=\left(47.53-53.47\right)-47.37+53.37\)

\(=0-37.\left(47-53\right)\)

\(=0-37.\left(-6\right)\)

\(=0-\left(-222\right)\)

\(=222\)

\(2016.83+1008.34\)

\(=167328+34272\)

\(=201600\)

\(\left(37.13-13\right):\left(24+37.12\right)\)

\(=\frac{37.13-13}{24+37.12}\)

\(=\frac{13.\left(37-1\right)}{12.2+37.12}\)

\(=\frac{13.36}{12.\left(2+37\right)}\)

\(=\frac{13.36}{12.39}\)

\(=\frac{13.12.3}{12.13.3}\)

\(=\frac{13.12.3}{13.12.3}\)

\(=1\)

~ Rất vui vì giúp đc bn ~

Lầm sau đăng từng cái 1 ik, như thế sẽ dễ hơn, thế này nhìn rắc rối lắm !!! ^_<

\(1\dfrac{13}{15}\cdot0,75\cdot\left(\dfrac{8}{15}+0.25\right)\cdot\dfrac{24}{47}\)

= \(\dfrac{28}{15}\cdot\dfrac{3}{4}\cdot\left(\dfrac{8}{15}+\dfrac{1}{4}\right)\cdot\dfrac{24}{47}\)

= \(\dfrac{7}{5}\cdot\dfrac{47}{60}\cdot\dfrac{24}{47}\)

\(=\dfrac{329}{300}\cdot\dfrac{24}{47}\)

\(=\dfrac{14}{25}\)

14/25

= 28/15 x 3/4  ( 8/15 +  1/4 ) x 24/27

= 28/15 x 3/4 . 47/60 x 24/27

= 7/5 x  47/60 x 24/27

= 658/675

 -29.(85-47)-85.(47-29)

=-29.38-85.18

=-1102-1503

=-2605

-15.(23-29)+23-(15-29)

=-15.(-6)+23-(-14)

=90+23+14

=113+14

=127

 -13.(55-29)+23.(15-29)

=-13.26+23.(-14)

=-338+(-322)

=-660

-10.(2+4)-5.(4-3)

=-10.6-5.1

=-60-5

=-65

\(\dfrac{8}{13}+\dfrac{4}{9}+\dfrac{1}{3}+\dfrac{5}{13}+3\)

\(=1+\dfrac{7}{9}+3\)

\(=4+\dfrac{7}{9}=\dfrac{43}{9}\)