Kết quả :    Viết lại biểu thức đã cho 

           =>         -7/4x . ( 33/12 + 33/20 + 33/30 + 33/42  ) = 22 

                    -7/4x . 33 . ( 1/12 + 1/20 + 1/30 + 1/42 )   = 22 

           -231/4x    . ( 1/3 . 4 + 1/ 4. 5 + 1/5 . 6 + 1/ 6. 7 ) = 22

-231/4x    . ( 1/3 - 1/4 + 1/4 - 1/5 + 1/5 - 1/6 + 1/6 - 1/7 ) = 22 

                                                -231/4x    . ( 1/3 - 1/7 ) = 22  

                                                -231/4x     .  4/21         = 22 

                                                                -11x            = 22 

                                                                    x             = 22 : -11

                                                                    x             = -2 

                                                      Vậy        x             = -2 

\(P=-\frac{7}{4}.\left(\frac{33}{12}+\frac{3333}{2020}+\frac{333333}{303030}+\frac{33333333}{42424242}\right)\)

\(P=-\frac{7}{4}.\left(\frac{33}{12}+\frac{33.101}{20.101}+\frac{33x10101}{30x10101}+\frac{33x1010101}{42x1010101}\right)\)

\(P=-\frac{7}{4}.\left(\frac{33}{12}+\frac{33}{20}+\frac{33}{30}+\frac{33}{42}\right)\)

\(P=-\frac{7}{4}.\left(\frac{11}{4}+\frac{33}{20}+\frac{11}{10}+\frac{11}{14}\right)\)

\(P=-\frac{77}{8}.\left(\frac{1}{6}+\frac{3}{10}+\frac{1}{15}+\frac{1}{21}\right)=-\frac{77}{8}.\frac{35+63+14+10}{210}=-\frac{11x122}{8x30}\)

\(P=-\frac{671}{120}\)

P = -7/4 x (33/12 + 3333/2020 + 333333/303030 + 33333333/42424242)
   = -7/4 x (33/12 + 33/20 + 33/30 + 33/42)
   = -7/4 x [33 x (1/12 + 1/20 + 1/30 + 1/42)]
   = -7/4 x [33 x (35/420 + 21/420 + 14/420 + 10/420)]
   = -7/4 x (33 x 80/420)
   = -7/4 x  33 x 4/21
   = -7/4 x 4/21 x 33 (= -7x4 / 4x21   x33)
   = -7/21 x 33 (= -7x33 / 21 = -1x7x3x11 / 3x7)
   = -11/1
   = -11
Đáp số P = -11

Các số gạch đi là do rút gọn phân số nhé!!!

\(\frac{7}{4}\left(\frac{33}{12}+\frac{3333}{2020}+\frac{333333}{303030}+\frac{33333333}{42424242}\right)\)

=\(\frac{7}{4}\left(\frac{33}{12}+\frac{33}{20}+\frac{33}{30}+\frac{33}{42}\right)\)

=\(\frac{7}{4}.33\left(\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\right)\)

=\(\frac{231}{4}\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)

=\(\frac{231}{4}\left(\frac{1}{3}-\frac{1}{7}\right)\)

=\(\frac{231}{4}.\frac{4}{21}\)

= 11

\(\dfrac{-7}{4}.\left(\dfrac{33}{12}+\dfrac{3333}{2020}+\dfrac{333333}{303030}+\dfrac{33333333}{42424242}\right)\)

\(=\dfrac{-7}{4}.\left(\dfrac{33}{12}.\dfrac{33.101}{20.101}.\dfrac{33.10101}{30.10101}.\dfrac{33.1010101}{42.1010101}\right)\)

\(=\dfrac{-7}{4}.\left(\dfrac{33}{12}.\dfrac{33}{20}.\dfrac{33}{30}.\dfrac{33}{42}\right)\)

\(=\dfrac{-7}{4}.33.\left(\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}\right)\)

\(=\dfrac{-7}{4}.33.\left(\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{7}\right)\)

\(=\dfrac{-7}{4}.33.\left(\dfrac{1}{3}-\dfrac{1}{7}\right)\)

\(=\dfrac{-7}{4}.33.\dfrac{4}{21}\)

\(=33.\dfrac{-1}{3}\)

\(=11\)

xl nhé kết quả là -11 mk viết thiếu dấu -

Cái ở giữa 3333/2020 và 333333/3030303 là j vậy ạ

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