a, =(94/7+57/13)-8.3/7

=(1222/91+399/91)-8.3/7

=1621/91-24/7

=187/13

b,=(6/1-14/5).25/8-8/5:1/4

=(30/5-14/5).25/8-8/5.4/1

=16/5.25/8-32/5

=10-32/5

=10/1-32/5

=50/5-32/5

=18/5

\(1-\left(5\frac{4}{9}+y-7\frac{7}{18}\right):15\frac{3}{4}=0\)

\(1-\left(\frac{49}{9}+y-\frac{133}{18}\right):\frac{63}{4}=0\)

\(1-\left(\frac{49}{9}+y-\frac{133}{18}\right)\times\frac{4}{63}=0\)

\(1-\frac{28}{81}-y\times\frac{4}{63}+\frac{38}{81}=0\)

\(1+\frac{38}{81}-\frac{28}{81}-y\times\frac{4}{63}=0\)

\(1+\frac{10}{81}-y\times\frac{4}{63}=0\)

\(\frac{91}{81}-y\times\frac{4}{63}=0\)

\(y\times\frac{4}{63}=\frac{91}{81}\)

\(y=\frac{91}{81}:\frac{4}{63}\)

\(y=\frac{637}{36}\)

P/s : Số hơi to 

\(1-\left(5\frac{4}{9}+y-7\frac{7}{18}\right):15\frac{3}{4}=0\)

\(\Rightarrow1-\left(\frac{49}{9}+y-\frac{133}{18}\right):\frac{63}{4}=0\)

\(\Rightarrow\left(\frac{98}{18}+y-\frac{133}{18}\right):\frac{63}{4}=1-0\)

\(\Rightarrow\left(-\frac{35}{18}+y\right):\frac{63}{4}=1\)

\(\Rightarrow-\frac{35}{18}+y=1\times\frac{63}{4}\)

\(\Rightarrow\frac{-35}{18}+y=\frac{63}{4}\)

\(\Rightarrow y=\frac{63}{4}--\frac{35}{18}\)

\(\Rightarrow y=\frac{63}{4}+\frac{35}{18}\)

\(\Rightarrow y=\frac{637}{36}\)

Vậy \(y=\frac{637}{36}\)

\(1-\left(5\frac{4}{9}+y-7\frac{7}{18}\right):15\frac{3}{4}=0\)

=> \(\left(5\frac{4}{9}+y-7\frac{7}{18}\right):15\frac{3}{4}=1-0\)

=> \(\left(\frac{49}{9}+y-\frac{133}{18}\right):\frac{63}{4}=1\)

=> \(\left(\frac{49}{9}-\frac{133}{18}\right)+y=1\cdot\frac{63}{4}\)

=>  \(\left(-\frac{35}{18}\right)+y=\frac{63}{4}\)  =>  \(y=\frac{63}{4}-\left(-\frac{35}{18}\right)=\frac{63}{4}+\frac{35}{18}\)

=>  \(y=\frac{637}{36}\)

Chúc bạn hk tốt!! k cho mình na

Bài 1: tính: a) 8 và 5/9 : 5 và 1/2 b) 7 và 3/4 - 2 và 1/8 c) 1 và 3/4 x 2 và 5/6 d) 7 - 2 và 2/3 e) 2 và 3/7 x 1 và 3/4 g) 5 và 1/3 : 3 và 1/5 Bài 2: tìm X: X : 3 và 1/3= 2 và 2/5 + 7/10 Và là biểu thị cho hỗn số nhé

Bài 1:

a, 85995​:51221​

= 779977​: 112211​

= 779977​ x 211112​

= 149914​
 

b, 73443​ - 21881​

= 314431​ - 178817​

= 458845​

c, 13443​ x 25665​

= 7447​ x 176617​

= 1192424119​
 

d, 7 - 22332​

= 213321​ - 8338​

= 133313​
 

e, 23773​ x 13443​

= 177717​ x 7447​

= 174417​
 

g, 51331​: 31551​

= 163316​ : 165516​

= 5335​
 

Bài 2: 

$x$: 31331​ = 25775​ + 710107​

$x$ : 103310​ = 197719​ + 710107​

$x$ : 103310​ = 2397070239​

$x$         = 2397070239​ x 103310​

$x$         = 2392121239​
 

C1:

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

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

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

A = \(1+2\frac{1}{3}\)

A = \(1+\frac{7}{3}\)

A = \(\frac{10}{3}\)

C2:

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

A = \(\frac{26}{7}+\frac{14}{3}-\frac{19}{7}-\frac{7}{3}\)

A = \(1+\frac{14}{3}-\frac{7}{3}=\frac{10}{3}\)

C1: Ta có: \(B=8\frac{1}{9}-3\frac{2}{7}+6\frac{8}{7}-3\frac{5}{7}\)

\(=8+\frac{1}{9}-\left(3+\frac{2}{7}\right)+6+\frac{8}{7}-\left(3+\frac{5}{7}\right)\)

\(=8+\frac{1}{9}-3-\frac{2}{7}+6+1+\frac{1}{7}-3-\frac{5}{7}\)

= \(\left(8-3+6+1-3\right)+\left(\frac{1}{9}-\frac{2}{7}+\frac{1}{7}-\frac{5}{7}\right)\)

\(=9+\left(\frac{-47}{63}\right)\)

 \(=\frac{520}{63}\)

C2: Đổi hỗn số ra phân số rồi tính ( cj nghĩ thế )

a: \(\Leftrightarrow\left(\dfrac{13}{4}:x\right)\cdot\left(-\dfrac{5}{4}\right)=\dfrac{-10}{6}-\dfrac{5}{6}=\dfrac{-15}{6}=\dfrac{-5}{2}\)

\(\Leftrightarrow\dfrac{13}{4}:x=\dfrac{5}{2}\cdot\dfrac{5}{4}=\dfrac{25}{8}\)

hay \(x=\dfrac{13}{4}:\dfrac{25}{8}=\dfrac{13}{4}\cdot\dfrac{8}{25}=\dfrac{26}{25}\)

b: \(\Leftrightarrow\dfrac{3}{4}:x=\dfrac{11}{36}-\dfrac{1}{4}=\dfrac{2}{36}=\dfrac{1}{18}\)

=>\(x=\dfrac{3}{4}:\dfrac{1}{18}=\dfrac{54}{4}=\dfrac{27}{2}\)

c: \(\Leftrightarrow\left(-\dfrac{6}{5}+x\right):\left(-3.6\right)=-\dfrac{7}{4}+\dfrac{1}{4}\cdot8=\dfrac{1}{4}\)

=>x-6/5=-9/10

=>x=3/10

\(4\frac{5}{7}:1=\frac{33}{7}:1==\frac{33}{7}\)

\(\frac{5}{6}+2=\frac{5}{6}+\frac{12}{6}=\frac{17}{6}\)

\(\frac{7}{15}x\frac{21}{74}=\frac{7}{3x5}x\frac{3x7}{74}=\frac{7x7}{5x74}=\frac{49}{370}\)

a)\(\left(x+3\right)\times5+1=20\Leftrightarrow5x+15=19\)

\(\Leftrightarrow5x=4\Leftrightarrow x=\frac{4}{5}\)

b)sai đề

c)\(2\frac{3}{7}\times x+1\frac{5}{4}=5\frac{3}{42}\)\(\Leftrightarrow\frac{17}{7}\times x+\frac{9}{4}=\frac{71}{14}\) \(\Leftrightarrow\frac{17}{7}\times x+\frac{63}{28}=\frac{142}{28}\)

\(\Leftrightarrow\frac{17}{7}\times x=\frac{79}{28}\Leftrightarrow x=\frac{17}{7}:\frac{79}{28}\) \(\Leftrightarrow x=\frac{17}{7}\times\frac{28}{79}\Leftrightarrow x=\frac{476}{553}=\frac{68}{79}\)

d)\(10\frac{2}{3}-x:\frac{6}{7}=8\frac{1}{3}-6\frac{2}{7}\Leftrightarrow\frac{32}{3}-x:\frac{6}{7}=\frac{25}{3}-\frac{44}{7}\) \(\Leftrightarrow\frac{224}{21}-x:\frac{6}{7}=\frac{75}{21}-\frac{132}{21}\Leftrightarrow-\frac{57}{21}-\frac{224}{21}\)

\(\Leftrightarrow-x:\frac{6}{7}=-\frac{281}{21}\Leftrightarrow-x=-\frac{281}{21}\times\frac{6}{7}\) \(\Leftrightarrow-x=-\frac{1686}{147}\Leftrightarrow x=\frac{562}{49}=11\frac{23}{49}\)