\(\dfrac{-4}{11}\cdot\dfrac{2}{5}+\dfrac{6}{11}\cdot\dfrac{-3}{11}\)
Tính hợp lý:
\(a.\dfrac{3}{17}+\dfrac{-5}{13}+\dfrac{-18}{35}+\dfrac{14}{17}+\dfrac{17}{-35}+\dfrac{-8}{13}\)
\(b.\dfrac{-3}{8}\cdot\dfrac{1}{6}+\dfrac{3}{-8}\cdot\dfrac{5}{6}+\dfrac{-10}{16}\)
\(c.\dfrac{-4}{11}\cdot\dfrac{5}{15}\cdot\dfrac{11}{-4}\)
a: \(=\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{-5}{13}-\dfrac{8}{13}\right)+\left(\dfrac{-18}{35}-\dfrac{17}{35}\right)\)
=1-1-1
=-1
b: \(=\dfrac{-3}{8}\left(\dfrac{1}{6}+\dfrac{5}{6}\right)+\dfrac{-5}{8}=\dfrac{-3}{8}-\dfrac{5}{8}=-1\)
c: \(=\dfrac{4}{4}\cdot\dfrac{5}{15}\cdot\dfrac{11}{11}=\dfrac{1}{3}\)
a) \(=\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(-\dfrac{5}{13}+-\dfrac{8}{13}\right)+\left(-\dfrac{18}{35}+-\dfrac{17}{35}\right)=1+-1+-1=-1\)
b) \(=-\dfrac{3}{8}\cdot\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}=-\dfrac{3}{8}-\dfrac{10}{16}=-1\)
c) \(=\left(-\dfrac{4}{11}\cdot-\dfrac{11}{4}\right)\cdot\dfrac{5}{15}=1\cdot\dfrac{1}{3}=\dfrac{1}{3}\)
a)\(=\left(-\dfrac{5}{13}+\dfrac{-8}{13}\right)+\left(-\dfrac{18}{35}-\dfrac{17}{35}\right)+\left(\dfrac{3}{14}+\dfrac{14}{17}\right)=-1-1+1=-1\)
b)\(=\dfrac{-3}{8}.\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}=-\dfrac{3}{8}.1-\dfrac{10}{16}=-\dfrac{6}{16}-\dfrac{10}{16}=-\dfrac{16}{16}=-1\)
c)\(\dfrac{-4.5.11}{11.5.3.-4}=\dfrac{1}{3}\)
\(Q=\dfrac{5}{11}\cdot\dfrac{2}{17}+\dfrac{7}{17}\cdot\dfrac{-6}{11}-\dfrac{9}{17}\cdot\dfrac{5}{11}\)
\(Q=\dfrac{5}{11}.\dfrac{2}{17}+\dfrac{7}{17}.\dfrac{-6}{11}-\dfrac{9}{17}.\dfrac{5}{11}\)
\(Q=\dfrac{5}{11}\left(\dfrac{2}{17}-\dfrac{9}{17}\right)+\dfrac{7}{17}.\dfrac{-6}{11}\)
\(Q=\dfrac{5}{11}.\dfrac{-7}{17}+\dfrac{-7}{17}.\dfrac{6}{11}\)
\(Q=\dfrac{-7}{17}.\left(\dfrac{5}{11}+\dfrac{6}{11}\right)\)
\(Q=\dfrac{-7}{17}\)
\(\dfrac{-4}{11}\cdot\dfrac{2}{5}+\dfrac{6}{11}\cdot\dfrac{-3}{10}\)
\(-\dfrac{4}{11}.\dfrac{2}{5}+\dfrac{6}{11}.-\dfrac{3}{10}\)
\(=-\dfrac{8}{55}+-\dfrac{9}{55}\)
\(=\dfrac{-8+-9}{55}\)
\(=-\dfrac{17}{55}\)
Nhớ ủng hộ 1 Đúng !
Tính giá trị biểu thức :
\(\dfrac{6:\dfrac{3}{5}-1\dfrac{1}{6}\cdot\dfrac{6}{7}}{4\dfrac{1}{5}\cdot\dfrac{10}{11}+5\dfrac{2}{11}}\).
\(\dfrac{6:\dfrac{3}{5}-1\dfrac{1}{6}\cdot\dfrac{6}{7}}{4\dfrac{1}{5}\cdot\dfrac{10}{11}+5\dfrac{2}{11}}\)
\(=\dfrac{6\cdot\dfrac{5}{3}-\dfrac{7}{6}\cdot\dfrac{6}{7}}{\dfrac{21}{5}\cdot\dfrac{10}{11}+\dfrac{57}{11}}\)
\(=\dfrac{10-1}{462+\dfrac{57}{11}}\)
\(=\dfrac{9}{467,\left(18\right)}\)
Tìm x, biết:
\(x=\dfrac{19}{11}\cdot\dfrac{5}{14}+\dfrac{1}{11}\cdot\dfrac{5}{7}-\sqrt{\dfrac{25}{4}}\cdot\dfrac{2}{11}\)
Thực hiện phép tính (tính nhanh nếu có thể)
\(\dfrac{5}{11}\cdot\dfrac{5}{7}+\dfrac{5}{11}\cdot\dfrac{2}{7}+\dfrac{6}{11}\)
\(=\dfrac{5\left(5+2\right)}{11.7}+\dfrac{6}{11}=\dfrac{5}{11}+\dfrac{6}{11}=1\)
Ta có:
= 5/11 .( 5/7+ 2/7 ) + 6/11
= 5/11 . 1 + 6/11
= 11/ 11
= 1
#học tốt ạ :3
Thực hiện phép tính: (2 điểm)
a) $1-\dfrac{1}{2}+\dfrac{1}{3}$ ;
b) $\dfrac{2}{5}+\dfrac{3}{5}: \dfrac{9}{10}$ ;
c) $\dfrac{7}{11} \cdot \dfrac{3}{4}+\dfrac{7}{11} \cdot \dfrac{1}{4}+\dfrac{4}{11}$ ;
d) $\left(\dfrac{3}{4}+0,5+25 \%\right) \cdot 2 \dfrac{2}{3}$ .
a) = 1/2 + 1/3 = 5/6
b) = 2/5 + 2/3 = 16/15
c) = 7/11 . ( 3/4 + 1/4 ) + 4/11
= 7/11 . 1 + 4/11
= 7/11 + 4/11
= 1
d) = ( 3/4 + 1/2 + 1/4 ) . 8/3
= 3/2 . 8/3
= 4
Câu 1.
a) 1-\(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)= \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)=\(\dfrac{3}{6}\)+\(\dfrac{2}{6}\)=\(\dfrac{5}{6}\)
b) \(\dfrac{2}{5}\)+\(\dfrac{3}{5}\):\(\dfrac{9}{10}\)= 1 :\(\dfrac{9}{10}\)= \(\dfrac{10}{9}\)
c) \(\dfrac{7}{11}\).\(\dfrac{3}{4}\)+\(\dfrac{7}{11}\).\(\dfrac{1}{4}\)+\(\dfrac{4}{11}\)=\(\dfrac{7}{11}\).1+\(\dfrac{4}{11}\)=1
(0,5 điểm) Tính.
$\dfrac{11}{3} \cdot \dfrac{2}{5}+\dfrac{11}{3} \cdot \dfrac{8}{5}-\dfrac{11}{3}$
11/3 . 2/5 + 11/3 . 8/5 - 11/3
= 11/3 . (2/5 + 8/5 - 1)
= 11/3 . (2 - 1)
= 11/3 . 1
= 11/3
\(\dfrac{11}{3}\)⋅\(\dfrac{2}{5}\)+\(\dfrac{11}{3}\).\(\dfrac{8}{5}\)-\(\dfrac{11}{3}\)
= \(\dfrac{11}{3}\).(\(\dfrac{2}{5}\) + \(\dfrac{8}{5}\) - 1)
= \(\dfrac{11}{3}\).(2 - 1)
= \(\dfrac{11}{3}\) . 1
=\(\dfrac{11}{3}\)
a) \(\left(7\dfrac{4}{9}+3\dfrac{7}{11}\right)-3\dfrac{4}{9}\)
b) \(5\dfrac{2}{7}\cdot\dfrac{8}{11}+5\dfrac{2}{7}\cdot\dfrac{5}{11}-5\dfrac{2}{7}\cdot\dfrac{2}{11}\)
c) \(1\dfrac{13}{15}\cdot0,75-\left(\dfrac{11}{20}+25\%\right):\dfrac{7}{5}\)
Giúp mình nha
Đang cần gấp
A,
\(\left(7\dfrac{4}{9}+3\dfrac{7}{11}\right)-3\dfrac{4}{9}=7\dfrac{4}{9}+3\dfrac{7}{11}-3\dfrac{4}{9}\)
\(=7\dfrac{4}{9}-3\dfrac{4}{9}+3\dfrac{7}{11}=4+3\dfrac{7}{11}=7\dfrac{7}{11}\)
B,
\(5\dfrac{2}{7}.\dfrac{8}{11}+5\dfrac{2}{7}.\dfrac{5}{11}-5\dfrac{2}{7}.\dfrac{2}{11}=5\dfrac{2}{7}.\left(\dfrac{8}{11}+\dfrac{5}{11}-\dfrac{2}{11}\right)\)
\(=5\dfrac{2}{7}.1=5\dfrac{2}{7}\)
C,
\(1\dfrac{13}{15}.0,75-\left(\dfrac{11}{20}+25\%\right):\dfrac{7}{5}=\dfrac{28}{15}.\dfrac{3}{4}-\left(\dfrac{11}{20}+\dfrac{1}{4}\right).\dfrac{5}{7}\)
\(=\dfrac{7}{5}-\dfrac{3}{5}.\dfrac{5}{7}=\dfrac{7}{5}-\dfrac{3}{7}=\dfrac{34}{35}\)