a: =11/4+5/4-9/8

=4-9/8=32/8-9/8=23/8

b: \(=\dfrac{6}{7}\cdot\dfrac{7}{4}+\dfrac{5}{3}=\dfrac{3}{2}+\dfrac{5}{3}=\dfrac{9+10}{6}=\dfrac{19}{6}\)

c: \(=\dfrac{13}{18}\cdot\dfrac{9}{5}-1=\dfrac{13}{10}-1=\dfrac{3}{10}\)

d: \(=3+\dfrac{9}{4}\cdot\dfrac{5}{3}=3+\dfrac{45}{12}=\dfrac{81}{12}=\dfrac{27}{4}\)

`a)11/4+5/4-9/8=4-9/8=32/8-9/8=23/8`

`b)6/7 xx 7/4+5/3=3/2+5/3=9/6+10/6=19/6`

`c)13/18xx9/5−1=13/10−1=3/10`

`d)3+9/4xx5/3=3+45/12=27/4`

1, Ta có :

     \(x+\frac{3}{5}=\frac{4}{7}\div\frac{8}{21}\)

    \(x+\frac{3}{5}=\frac{4}{7}\times\frac{21}{8}\)

    \(x+\frac{3}{5}=\frac{3}{2}\)

    \(x=\frac{3}{2}-\frac{3}{5}\)

    \(x=\frac{15}{10}-\frac{6}{10}\)

    \(x=\frac{9}{10}\)

Vậy x = \(\frac{9}{10}\)

2, Ta có :

    \(\frac{2}{3}+\frac{3}{4}\div x=-\frac{1}{6}\)

    \(\frac{3}{4}\div x=-\frac{1}{6}-\frac{2}{3}\)

    \(\frac{3}{4}\div x=-\frac{1}{6}-\frac{4}{6}\)

    \(\frac{3}{4}\div x=-\frac{5}{6}\)

    \(x=\frac{3}{4}\div\left(-\frac{5}{6}\right)\)

    \(x=\frac{3}{4}\times\left(-\frac{6}{5}\right)\)

    \(x=-\frac{9}{10}\)

Vậy x = \(-\frac{9}{10}\)

thanks bạn nha

a) \(\left(\frac{3}{5}x-\frac{2}{3}x-x\right).\frac{1}{7}=\frac{-5}{21}\)

\(\Rightarrow\left(\frac{3}{5}-\frac{2}{3}-1\right).x=\frac{-5}{21}:\frac{1}{7}=\frac{-5}{3}\)

\(\Rightarrow\frac{-16}{15}.x=\frac{-5}{3}\Rightarrow x=\frac{-5}{3}:\frac{-16}{15}=\frac{25}{16}\)

b) \(\left(x-\frac{1}{4}\right)^2=\frac{1}{36}\)

\(\Rightarrow\left(x-\frac{1}{4}\right)^2=\left(±\frac{1}{6}\right)^2\)

\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{4}=\frac{1}{6}\\x-\frac{1}{4}=\frac{-1}{6}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{5}{12}\\x=\frac{1}{12}\end{cases}}\)

c) \(14-\left|\frac{3x}{2}-1\right|=9\)

\(\Rightarrow\left|\frac{3x}{2}-1\right|=14-9=5\)

\(\Rightarrow\orbr{\begin{cases}\frac{3x}{2}-1=5\\\frac{3x}{2}-1=-5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\frac{3x}{2}=6\\\frac{3x}{2}=-4\end{cases}}\Rightarrow\orbr{\begin{cases}3x=12\\3x=-8\end{cases}}\Rightarrow\orbr{\begin{cases}x=4\\x=\frac{-8}{3}\end{cases}}\)

kết quả là -40

chính xác đấy

nha

10 - [ ( 9 . 7 + 21 ) : 2 + 8 ]

= 10 - [ 84 : 2 + 8 ]

= 10 - 50

= 50

= 10 - [(21 + 21): 2 + 8]

= 10 - [42 : 2 + 8 ]

= 10 - [ 21 + 8 ]

= 10 - 29

= (-19)

\(\frac{5}{4}+\frac{9}{2}-\frac{8}{6}\)

\(=\frac{15}{12}+\frac{54}{12}-\frac{16}{12}\)

\(=\frac{53}{12}\)

Chúc bạn học tốt !

5/4=60/48

9/2=216/48

8/6=64/48

đáp số 212/48

5/4 + 9/2 - 8/6 

= 15/12 + 54/12 - 16/12

=53/12

\(\dfrac{21}{36}-\left(-\dfrac{11}{30}\right)=\dfrac{7}{12}+\dfrac{11}{30}=\dfrac{7.5+11.2}{60}=\dfrac{57}{60}=\dfrac{19}{20}\\ ----\\\dfrac{-4}{8}+\left(-\dfrac{3}{10}\right)=\dfrac{-1}{2}-\dfrac{3}{10}=\dfrac{-1.5-3}{10}=\dfrac{-8}{10}=-\dfrac{4}{5}\\ ----\\ \dfrac{7}{12}-\left(-\dfrac{9}{20}\right)=\dfrac{7}{12}+\dfrac{9}{20}=\dfrac{7.5+9.3}{60}=\dfrac{62}{60}=\dfrac{31}{30}\\ ---\\ \dfrac{-2}{5}+\left(-\dfrac{11}{30}\right)=-\dfrac{2}{5}-\dfrac{11}{30}=\dfrac{-2.6-11}{30}=-\dfrac{29}{30}\)

Giải :

-7/12 + 11/8 - 5/9

=  17/72

Học tốt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

lấy tổng của 7/12 và 11/8 trừ đi 5/9 bằng 17/72

#hok tốt

Đáp số: \(\frac{17}{72}\)

~~~Hok tốt~~~

= (12-12) + (11+10) - (9+8) - (7+5) - (4+3) + (2-1)

= 0 + 21 - 17 - 12 - 7 + 1

= 21- 17 - 12 - 7 +1

= 4 - 12 - 7 +1

= -8 - 7 + 1

= -15 + 1

= -14

hết

= 12 - 12 + 11 + ( 10 - 9 ) + ( 8 - 7 ) + ( 5 - 4 ) + 3 + ( 2 -1 ) 

= 0 + 11 + 1 + 1 + 1 + 3 + 1

= 11 +1 + 1 + 1 + 3 + 1

= 12 + 1 + 1 + 3 + 1 

= 13 + 1 + 3 + 1

= 14 + 3 + 1

= 17 + 1 

= 18

Đáp án đây nha bạn !!!

Chúc bạn học tốt !!!