a)\(\frac{5}{9}\times x-1=\frac{8}{9}\)

\(\frac{5}{9}\times x=\frac{8}{9}+1\)

\(\frac{5}{9}\times x=\frac{17}{9}\)

\(x=\frac{17}{9}:\frac{5}{9}\)

\(x=\frac{17}{5}\)

b)\(x+x\times\frac{1}{3}:\frac{2}{9}+x:\frac{2}{7}=252\)

\(x+x\times\frac{3}{2}+x:\frac{2}{7}=252\)

\(x.1+x.\frac{3}{2}+x.\frac{7}{2}=252\)

\(x\left(1+\frac{3}{2}+\frac{7}{2}\right)=252\)

\(x\times6=252\)

\(x=252:6\)

\(x=42\)

a,5/9.x-1=8/9

5/9.x=17/9

x=17/5

b,x+x.1/3:2/9+x:2/7=252

x+x.1/3.9/2+x.7/2=252

x(1+1/3.9/2+7/2)=252

x.6=252

x=42

Ta có : (x + 2) + (x + 5) + (x + 8) + ...... + (x + 32) = 198

<=> (x + x + x + ...... + x) + (2 + 5 + 8 + ....... + 32) = 198

<=> 11x + 187 = 198

=> 11x = 198 - 187

=> 11x = 11

=> x = 1

a . 

 \(x+x\times\frac{1}{3}\div\frac{2}{9}+x\div\frac{2}{7}=252\)

\(x+x\times\frac{3}{2}+x=252\times\frac{2}{7}\)

\(x+x\times\frac{3}{2}+x=72\)

\(x=72\div\frac{3}{2}-3x\)

\(x=48-3x\)

\(x=45\)

\(\left(x+2\right)+\left(x+5\right)+\left(x+8\right)+....\left(x+32=198\right)\)

chẳng hiểu gì 

ko hiểu thì thôi Lê Đăng Dương

a) 70.5

b) 12600

y+y x 1/3 : 2/9 + y :2/7 = 252

y x 1 + y x (1/3 x 9/2 ) + y x 7/2 = 252

y x 1/1 + y x 3/2 + y x 7/2 = 252

y x (1/1 + 3/2 + 7/2 ) = 252

y x 6 = 252

y = 252 : 6

y = 42

B = \(\frac{1}{10.9}+\frac{1}{18.13}+\frac{1}{26.17}+...+\frac{1}{802.405}\)

B = \(\frac{2}{10.18}+\frac{2}{18.26}+\frac{2}{26.34}+...+\frac{2}{802.810}\)

B = \(\frac{1}{4}.\left(\frac{1}{10}-\frac{1}{18}+\frac{1}{18}-\frac{1}{26}+\frac{1}{26}-\frac{1}{34}+...+\frac{1}{802}-\frac{1}{810}\right)\)

B = \(\frac{1}{4}.\left(\frac{1}{10}-\frac{1}{810}\right)=\frac{1}{4}.\frac{8}{81}\)

B = \(\frac{2}{81}\)

thank you bạn nha

Cô mik cũg cho bài này

\(y+y.\frac{1}{3}:\frac{2}{9}+y:\frac{2}{7}=252\)

=>\(y.\frac{2}{2}+y.\frac{3}{2}+y.\frac{7}{2}=252\)

=>\(y.\left(\frac{2}{2}+\frac{3}{2}+\frac{7}{2}\right)=252\)

=>\(y.6=252\)

=>y=252:6

=>y=42

y + y.1/3 : 2/9+y:2/7=252

=> y + y.1/3.9/2 + y.7/2=252

=> y + 2y + y(7/2)=252

=>y(1+2+7/2)=252

=>y.13/2=252

=>y=252.2/13=

=>Y+Y.1/3.9/2+Y.7/2=252

=>Y+3/2.Y+7/2.Y=252

=>Y(1+3/2+7/2)=252

=>Y.(2/2+3/2+7/2)=252

=>6Y=252

=>Y=4

VẬY Y=42

y+y nhân 1/3 :2/9+y nhân 2/7=252

y nhân 1+y nhân (1/3 nhân 9/2)+y nhân 7/2=252

y nhân 1/1+y nhân 3/2 +y nhân 7/2=252

y nhân(1/1+3/2+7/2)=252

y nhân 6=252

y =256:6

y=42

giải chi tiết giùm mình nhé 

nếu mà bạn giải xong rồi thì bạn nói cho mình biết nhen 

minh o van tit