=> 0,5.x:5-6,2=7,75-5

=> 0,5.x:5=2,75+6,2

=> 0,5.x=8,95.5

=> x=44,75:0,5

=> x=89,5

x=89,5

(\(\frac45:\frac65\) + \(\frac15\) : \(\frac{1}{x}\)) x 30 - 26 = 54

(\(\frac45\times\frac56\) + \(\frac15\times x\)) x 30 = 54 + 26

(\(\frac23+\frac15x\)) x 30 = 80

\(\frac23+\frac15x\) = 80 : 30

\(\frac23+\frac15x=\frac83\)

\(\frac15x=\frac83-\frac23\)

\(\frac15x\) = 2

\(x=2:\frac15\)

\(x=2\times5\)

\(x=10\)

Vậy \(x=10\)

6,3 x y + 3,7 x y = 100

y x (6,3 + 3,7) = 100

y x 10 = 100

y = 100 : 10

y = 10

Vậy y = 10

a) -2/3+3/4+1/6-2/5

=-40/60+45/60+10/60-24/60

=-9/60

=-3/20

b) -2/3-1/5+3/4-5/6+1/10

=-40/60-12/60+45/60-50/60+6/60

=-51/60

=-17/20

\(\frac{2}{5}.\frac{1}{x}+\frac{1}{x}.2+\frac{2}{5}=0,5\)

\(\Rightarrow\frac{2}{5x}+\frac{2}{x}+\frac{2}{5}=\frac{1}{2}\)

\(\Rightarrow2.\left(\frac{1}{5x}+\frac{1}{x}+\frac{1}{5}\right)=\frac{1}{2}\)

\(\Rightarrow\frac{1}{5x}+\frac{5}{5x}+\frac{x}{5x}=\frac{1}{2}:2=\frac{1}{4}\)

\(\Rightarrow\frac{1+5+x}{5x}=\frac{1}{4}\)

\(\Rightarrow4.\left(1+5+x\right)=5x\)

\(\Rightarrow4+20+4x=5x\)

\(\Rightarrow24+4x=5x\)

\(\Rightarrow5x-4x=24\)

\(\Rightarrow x=24\)

Trả lời

2/5.1/x+1/x.2+2/5=0,5

1/x.(2/5+2)+2/5   =1/2

1/x.12/5+2/5        =1/2

1/x.12/5               =1/2-2/5

1/x.12/5               =1/10

1/x                       =1/10:12/5

1/x                       =1/24.

Hình như mk làm sai !

`1/x + y/3 = 5/6`

`-> 1/x = 5/6 - y/3`

`-> 1/x = 5/6 - ( 2y ) / 6`

`-> 1/x = ( 5 - 2y ) / 6`

`-> x ( 5 - 2y ) = 6`

\(a,\frac{62}{7}:x=\frac{29}{9}:\frac{3}{56}\)

\(\frac{62}{7}:x=\frac{1624}{27}\)

\(x=\frac{62}{7}:\frac{1624}{27}=\frac{837}{5684}\)

\(b,\frac{1}{5}:x=\frac{1}{5}-\frac{1}{7}\)

\(\frac{1}{5}:x=\frac{2}{35}\)

\(x=\frac{1}{5}:\frac{2}{35}=\frac{7}{2}\)

\(c,\frac{2}{3}.x-\frac{4}{7}=\frac{1}{7}\)

\(\frac{2}{3}.x=\frac{1}{7}+\frac{4}{7}=\frac{5}{7}\)

\(x=\frac{5}{7}:\frac{2}{3}=\frac{15}{14}\)

\(d,\frac{2}{7}-\frac{8}{9}.x=\frac{2}{3}\)

\(\frac{8}{9}.x=\frac{2}{7}-\frac{2}{3}=-\frac{8}{21}\)

\(x=-\frac{8}{21}:\frac{8}{9}=-\frac{3}{7}\)

\(e,\frac{4}{7}+\frac{5}{9}:x=\frac{1}{5}\)

\(\frac{5}{9}:x=\frac{1}{5}-\frac{4}{7}=-\frac{13}{35}\)

\(x=\frac{5}{9}:-\frac{13}{35}=\frac{175}{117}\)

\(i,\frac{2}{5}-\frac{2}{5}.x=\frac{2}{5}\)

\(\frac{2}{5}.\left(1-x\right)=\frac{2}{5}\)

\(1-x=\frac{2}{5}:\frac{2}{5}=1\)

\(x=1-1=0\)

\(g,\frac{2}{3}+\frac{1}{3}:x=-1\)

\(\frac{1}{3}:x=-1-\frac{2}{3}=-\frac{5}{3}\)

\(x=\frac{1}{3}:-\frac{5}{3}=-\frac{1}{5}\)

học tốt nha