(131313/151515+ 131313/353535+131313/636363+131313/999999)*33

=(13/15+13/35+13/63+13/99)*33

=52/33*33

=52

131313 + 131313 + 131313 + 131313 / 151515 + 353535 + 6363636 + 999999

= 131313 x 4 / 10101 x ( 15 + 35 + 63 + 99)

= 10101 x 13 x 4 / 10101 x 212

= 10101 x 52 / 10101 x 212

= 13/53

131313/151515+131313/353535+131313/636363+131313/999999=13/15+13/35+13/63+13/99

=52/33=1/19/33

​DUYỆT NHÉ

thuy hang beautyful lam chuan

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left(\dfrac{131313}{151515}+\dfrac{131313}{353535}+\dfrac{131313}{636363}+\dfrac{131313}{999999}\right)=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left(\dfrac{13}{15}+\dfrac{13}{35}+\dfrac{13}{63}+\dfrac{13}{99}\right)=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left(\dfrac{13}{3.5}+\dfrac{13}{5.7}+\dfrac{13}{7.9}+\dfrac{13}{9.11}\right)=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left[\dfrac{13}{2}.\left(\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9}+\dfrac{2}{9.11}\right)\right]=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left[\dfrac{13}{2}.\left(\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{11}\right)\right]=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left[\dfrac{13}{2}.\left(\dfrac{1}{3}-\dfrac{1}{11}\right)\right]=-5\)

\(\dfrac{2}{3}x-70.\dfrac{10}{11}:\left[\dfrac{13}{2}.\dfrac{8}{33}\right]=-5\)

\(\dfrac{2}{3}x-\dfrac{700}{11}:\dfrac{52}{33}=-5\)

\(\dfrac{2}{3}x-\dfrac{525}{13}=-5\)

\(\dfrac{2}{3}x=-5+\dfrac{525}{13}=\dfrac{460}{13}\)

\(x\) = \(\dfrac{460}{13}:\dfrac{2}{3}=\dfrac{690}{13}\).

\(\Leftrightarrow\frac{2}{3}x-\frac{780}{11}:\left(\frac{13}{15}+\frac{13}{35}+\frac{13}{63}+\frac{13}{99}\right)=-5\)

\(\Leftrightarrow\frac{2}{3}x-40=0\)

\(\Leftrightarrow x=60\)