a) \(\left(4\frac{2}{3}-2\frac{2}{5}+7\frac{7}{13}\right)-\left(3\frac{5}{23}-6\frac{6}{13}\right)\)

=    \(4\frac{2}{3}-2\frac{2}{5}+7\frac{7}{13}-3\frac{5}{23}+6\frac{6}{13}\)

=     \(\left(4\frac{2}{3}-2\frac{2}{5}\right)+\left(7\frac{7}{13}+6\frac{6}{13}\right)-3\frac{5}{23}\)

=       \(2\frac{4}{15}+14-3\frac{5}{23}\)

=        \(16\frac{4}{15}-3\frac{5}{23}\)

=         \(13\frac{17}{345}\)

XIN LỖI NHA, MÌNH KO LÀM ĐƯỢC XONG CÂU b) , MONG BẠN THÔNG CẢM CHO MÌNH, KHI NÀO MÌNH NGHĨ RA CÂU b) MÌNH SẼ TRẢ LỜI

\(\frac{-575}{302}\)

Ta có :\(\frac{-17,5+\frac{5}{3}-2\frac{1}{7}}{7-\frac{2}{3}+\frac{6}{7}}=\frac{-17,5+\frac{5}{3}-\frac{15}{7}}{7-\frac{2}{3}+\frac{6}{7}}=\frac{-2,5\left(.7-\frac{2}{3}+\frac{6}{7}\right)}{7-\frac{2}{3}+\frac{6}{7}}=-2,5\)

C=\(\frac{-17,5+\frac{5}{3}-2\frac{1}{7}}{7,0-\frac{2}{3}+\frac{6}{7}}\)

  =\(\frac{\frac{-367,5}{21}+\frac{35}{21}-\frac{45}{21}}{\frac{147}{21}-\frac{14}{21}+\frac{18}{21}}\)

  =\(\frac{\frac{-377,5}{21}}{\frac{151}{21}}\)

  =\(-\frac{5}{2}\)

1/2+2/3+3/4+4/5+5/6+6/7+7/8+8/9+9/10x9/10

=9/10x(1/2+2/3)+(3/4+4/5)+(5/6+6/7)+(7/8+8/9)

=9/10x(1/3+3/5+5/7+7/9)

9/10x(1/3+3/5)+(5/7+7/9)

=9/10x1/5+5/9

9/50+5/9

=10

Bn Long làm đúng rồi bn   nguyễn kim arica cứ làm theo cách đó là được .

Bn nào thấy đúng thì ủng hộ nha .

hình như đề bạn sai thì phải đúng ko biết ngỏ bạn làm

cái chỗ có 2 phân số 9/10 đấy

\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5+\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)

\(=3-\frac{1}{4}+\frac{2}{3}-5-\frac{1}{3}+\frac{6}{5}-6+\frac{7}{4}-\frac{3}{2}\)

\(=\left(3-5-6\right)+\left(-\frac{1}{4}+\frac{7}{4}-\frac{3}{2}\right)+\left(\frac{2}{3}-\frac{1}{3}\right)+\frac{6}{5}\)

\(=-8+\frac{1}{3}+\frac{6}{5}\)

\(=-\frac{97}{15}\)

= 3 - 1/4 +2/3 - 5 - 1/3 + 6/5 - 6  + 7/4 - 3/2

= 2/3 . -3/2 . ( 3 + 5 + 6 ) . ( 2/3 + 1/3 ) . ( -1/4 - 7/4) 

= -1 . 14 . 1 . 6/4

= -14 . 1 . 6/4

= -14 . 6/4

= -84/4 = -21

\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5+\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)

\(=3+\frac{-1}{4}+\frac{2}{3}-5+\frac{-1}{3}+\frac{6}{5}-6+\frac{7}{4}+\frac{-3}{2}\)

\(=3+\frac{-1}{4}+\frac{2}{3}+-5+\frac{6}{5}+-\frac{1}{3}+-6+\frac{7}{4}+\frac{-3}{2}\)

\(=\left(3+-5+-6\right)+\left(-\frac{1}{4}+\frac{7}{4}\right)+\left(-\frac{1}{3}+\frac{2}{3}\right)+\frac{6}{5}+\frac{-3}{2}\)

\(=-8+\frac{3}{2}+\frac{1}{3}+\frac{6}{5}+\frac{-3}{2}\)

\(=\left(\frac{3}{2}+\frac{-3}{2}\right)+\left(\frac{6}{5}+\frac{1}{3}+-8\right)\)

\(=\frac{18}{15}+\frac{5}{15}+\frac{-120}{15}\)

\(=-\frac{97}{15}\)

\(\frac{-17,5+\frac{5}{3}-2\frac{1}{7}}{7-\frac{2}{3}+\frac{6}{7}}=\frac{\frac{-35}{2}+\frac{5}{3}-\frac{15}{7}}{\frac{14}{2}-\frac{2}{3}+\frac{6}{7}}=\frac{-5.\left(\frac{7}{2}-\frac{1}{3}+\frac{3}{7}\right)}{2.\left(\frac{7}{2}-\frac{1}{3}+\frac{3}{7}\right)}=\frac{-5}{2}=-2,5\)

hinh nhu bn chep sai dau bai

= \(6.\frac{4}{6}-3.\frac{4}{6}-2.\frac{-2}{3}+4\) \(=4-2+\frac{4}{3}+4=6\frac{4}{3}\)

\(6.\left(-\frac{2}{3}\right)^2-3.\left(-\frac{2}{3}\right)^2-2:\left(-\frac{3}{2}\right)+4\)\(\)\(\)

\(=6.\frac{4}{9}-3.\frac{4}{9}-2.\left(-\frac{2}{3}\right)+4\)

\(=\frac{4}{9}.\left(6-3\right)-2.\frac{-2}{3}+4\)

\(=\frac{4}{9}.3-2.\left(-\frac{2}{3}\right)+4\)

\(=\frac{2}{3}.2-2.\left(-\frac{2}{3}\right)+4\)

\(=-\frac{2}{3}.\left(-2-2\right)+4\)

\(=-\frac{2}{3}.\left(-4\right)+4\)

\(=\frac{8}{3}+\frac{12}{3}\)

\(=\frac{16}{3}\)

\(=3.\left(\frac{2}{3}\right)^2-2\left(\frac{-2}{3}\right)+4\)

\(=\frac{4}{3}+\frac{4}{3}+\frac{12}{3}\)

\(=\frac{20}{3}\)

Chắc vậy quá @@