=7/11+5/6+4/11-1/6

=(7/11+4/11)+(5/6-1/6)

=1+2/3

=5/3

\(A,\dfrac{7}{11}+\dfrac{5}{6}-\dfrac{-4}{11}-\dfrac{1}{6}\)

\(= (\dfrac{7}{11}+\dfrac{-4}{11})-(\dfrac{5}{6}-\dfrac{1}{6})\)

\(=\dfrac{3}{11}-\dfrac{2}{3}\)

\(= \dfrac{9}{33}-\dfrac{22}{33}\)

\(= \dfrac{-13}{33}\)

\(B,\dfrac{5}{9}.\dfrac{7}{3}+\dfrac{5}{9}.\dfrac{9}{13}-\dfrac{5}{9}:\dfrac{13}{5}\)

\(=(\dfrac{5}{9}.\dfrac{5}{9}:\dfrac{5}{9}).\dfrac{7}{3}+\dfrac{9}{13}-\dfrac{13}{5}\)

\(=(\dfrac{5}{9}.\dfrac{7}{3})+(\dfrac{9}{13}-\dfrac{13}{5})\)

\(=(\dfrac{5}{9}.\dfrac{21}{9})+(\dfrac{45}{65}-\dfrac{169}{65})\)

\(=\dfrac{35}{27}+\dfrac{-124}{65}\)

\(=\dfrac{2275}{1755}+\dfrac{-3348}{1755}\)

\(=\dfrac{-1073}{1755}\)

a, \(\frac{-3}{7}+\frac{5}{13}-\frac{4}{7}+\frac{8}{13}\)

\(=\frac{-3}{7}-\frac{4}{7}+\frac{5}{13}+\frac{8}{13}\)

\(=-\frac{7}{7}+\frac{13}{13}=-1+1=0\)

b, \(\frac{-5}{14}-\frac{2}{-14}+\frac{1}{8}+\frac{1}{8}\)

\(=\frac{-5}{14}+\frac{2}{14}+\frac{1}{8}+\frac{1}{8}\)

\(=-\frac{3}{14}+\frac{1}{4}=\frac{1}{28}\)

c,\(-\frac{5}{13}-\left(\frac{3}{5}+\frac{3}{13}-\frac{4}{10}\right)\)

\(=-\frac{5}{13}-\frac{3}{13}-\frac{3}{5}+\frac{4}{10}\)

\(=-\frac{8}{13}-\frac{3}{5}+\frac{4}{10}=-\frac{79}{65}+\frac{4}{10}=-\frac{53}{65}\)

d, \(\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{4}{6}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)

\(=\left[\left(\frac{1}{8}-\frac{9}{7}+\frac{2}{3}-\frac{12}{7}-\frac{1}{2}\right)+\frac{5}{9}\right]\)

\(=\left[\left(\frac{1}{8}-\frac{1}{2}-\frac{9}{7}-\frac{12}{7}+\frac{2}{3}\right)+\frac{5}{9}\right]\)

\(=-\frac{65}{24}+\frac{5}{9}=-2\frac{11}{72}\)

a)-3/7+5/13-4/7+8/13

=-3/7-4/7+5/13+8/13

=-7/7+13/13

=-1+1

=0

ta có \(\frac{\frac{4}{5}-\frac{4}{11}+\frac{4}{13}}{\frac{9}{5}-\frac{9}{11}+\frac{9}{13}}+\frac{\frac{5}{7}+\frac{5}{11}-\frac{5}{13}}{\frac{9}{7}+\frac{9}{11}-\frac{9}{13}}\)

       \(=\frac{4\left(\frac{1}{5}-\frac{1}{11}+\frac{1}{13}\right)}{9\left(\frac{1}{5}-\frac{1}{11}+\frac{1}{13}\right)}+\frac{5\left(\frac{1}{7}+\frac{1}{11}-\frac{1}{13}\right)}{9\left(\frac{1}{7}+\frac{1}{11}-\frac{1}{13}\right)}\)

           \(=\frac{4}{9}+\frac{5}{9}=\frac{9}{9}=1\)

5/13.9/7+5/7.2/13-5/13.4/7

= 5/13.(9/7-4/7) + 5/7.2/13

= 5/13.5/7+5/7.2/13

= 5/7.(5/13+2/13)

= 5/7.7/13

= 5/13

Một mảnh đất HCN có chiều dài 90cm chiều rộng bằng 3/5 chiều dài. Tính chu vi mảnh vườn đó

4/6 + 7/13 + 17/9 + 19/13 + 1/9 + 14/6

= ( 4/6 + 14/6 ) + ( 7/13 + 19/13 ) + ( 17/9 + 1/9 )

= 18/6 + 26/13 + 18/9

= 3 + 2 + 2 = 7

a,

\(\frac{8}{3}+\frac{17}{9}+\frac{19}{13}+\frac{1}{3}+\frac{7}{13}+\frac{1}{9}\)

\(=\left(\frac{8}{3}+\frac{1}{3}\right)+\left(\frac{17}{9}+\frac{1}{9}\right)+\left(\frac{19}{13}+\frac{7}{13}\right)\)

\(=3+2+2\)

\(=7\)

a) Số các số hạng trong A là: \(\left(25-1\right):1+1=25\) (số)

Tổng A bằng: \(\left(25+1\right)\cdot25:2=325\)

b) Số các số hạng trong B là: \(\left(50-2\right):2+1=25\) (số)

Tổng B bằng: \(\left(50+2\right)\cdot25:2=650\)

c) Số các số hạng trong C là: \(\left(81-1\right):4+1=21\) (số)

Tổng C bằng: \(\left(81+1\right)\cdot21:2=861\)

#Urushi

\(\frac{19}{13}+\frac{14}{16}+\frac{1}{9}+\frac{4}{6}+\frac{7}{13}+\frac{17}{9}\)

\(=\left(\frac{19}{13}+\frac{7}{13}\right)+\left(\frac{14}{6}+\frac{4}{6}\right)+\left(\frac{1}{9}+\frac{17}{9}\right)\)

\(=2+3+2\)

\(=7\)

chúc bạn học tootrs nha

19/13 + 14/16 + 1/9 + 4/6 + 7/13 + 17/9

= ( 19/13 + 7/13 ) + ( 14/16 + 4/6 ) + ( 1/9 + 17/9 )

= 26/13 + 37/24 + 18/9

= 2 + 37/24 + 2

=( 2 + 2 ) + 37/24

= 4 + 37/24

= 133/24.

1/3.(4/13-9/11)+1/3.(9/13-4/22)

=1/3(4/13-9/11+9/13-2/11)

=1/3(4/13+9/13-9/11-2/11)

=1/3(1-1)

=1/3.0=0