\(B=70.\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)

\(B=70.\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)

\(B=70.13.\left(\frac{1}{56}+\frac{1}{72}+\frac{1}{90}\right)\)

\(B=910.\left(\frac{1}{7.8}+\frac{1}{8.9}+\frac{1}{9.10}\right)\)

\(B=910.\left(\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}\right)\)

\(B=910.\left[\frac{1}{7}+\left(\frac{1}{8}-\frac{1}{8}\right)+\left(\frac{1}{9}-\frac{1}{9}\right)-\frac{1}{10}\right]\)

\(B=910.\left[\frac{1}{7}-\frac{1}{10}\right]\)

\(B=910.\frac{3}{70}=39\)

~ Hok tốt ~

#)Giải :

\(B=70.\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)

\(B=70.\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)( cùng chia cho 10101 )

\(B=70.\frac{39}{70}\)

\(B=39\)( trên dưới tử mẫu có 70 => loại )

        #~Will~be~Pens~#

70x(13/56+13/72+13/90)

\(70\cdot\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)

\(=70\cdot\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)

\(=70\cdot\frac{39}{70}\)

\(=70\)

\(B=70\cdot\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)

\(B=70\cdot\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)

\(B=70\cdot\frac{39}{70}\)

\(B=39\)

Vậy B = 39

B=\(70\times\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)

B=\(70\times\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)

B=\(70\times\frac{39}{70}\)

B=\(39\)

Nếu mk làm sai thì xin lỗi bạn nhiều nha

70.(13/56+13/72+13/90)

=70.39/70=39

đúg nha

B=39 tick cho mình nha nha nha nha

B=70.$\left(\genfrac{}{}{0ex}{}{13.10101}{56.10101}+\genfrac{}{}{0ex}{}{13.10101}{72.10101}+\genfrac{}{}{0ex}{}{13.10101}{90.10101}\right)$

B=70.$\left(\genfrac{}{}{0ex}{}{13}{56}+\genfrac{}{}{0ex}{}{13}{72}+\genfrac{}{}{0ex}{}{13}{90}\right)$

B=70.$\genfrac{}{}{0ex}{}{39}{70}$=39

nhớ tick cho mình nhe

B=70.\(\left(\frac{13.10101}{56.10101}+\frac{13.10101}{72.10101}+\frac{13.10101}{90.10101}\right)\)

B=70.\(\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)\)

B=70.\(\frac{39}{70}\)=39

ks nha

B= 70.( 131313/565656 + 131313/727272 + 131313/909090)

B = 70 * ( 13/56 + 13/72 + 13/90)

B = 70* 0,1464....

B= 10,254050...

Ta có: \(\frac{131313}{565656}=\frac{131313:10101}{565656:10101}=\frac{13}{56}\)

\(\frac{131313}{727272}=\frac{13}{72}\)

\(\frac{131313}{909090}=\frac{13}{90}\)

\(\Rightarrow C=70\left(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\right)=70\left(\frac{39}{79}\right)=39\)

Vậy C = 39

C=70(\(\frac{13}{56}+\frac{13}{72}+\frac{13}{90}\))=70\(\frac{39}{70}\)=39

\(C=70.\left(131313.\left(\dfrac{1}{565656}+\dfrac{1}{727272}+\dfrac{1}{909090}\right)\right)\)

\(C=70.\left(131313.\dfrac{1}{235690}\right)\)

\(C=70.\dfrac{39}{70}\)

\(C=39\)

a) A= ( 136/15 - 28/5 + 62/10) .21/24

A= (136/15 - 84/15 + 93/15) . 7/8

A= 145/15. 7/8

A= 203/24

b) B= 70 .( 131313.565656 + 131313/727272 + 131313/ 909090)

= 70. ( 13/56+ 13/72 + 13/90)

= 70 . 39/70

= 39