a: =>x:1/2=5/9

=>x=10/9

b: =>x*2/5=7/3

=>x=7/3:2/5=7/3*5/2=35/6

c: =>x=7/8-9/16=5/16

X=1/6

x=15/14

x=5/6-2/3

x=1/3

x=3/7:2/5

x=15/14

\(x=\dfrac{5}{6}-\dfrac{2}{3}=\dfrac{1}{6}\)

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

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

5.X/2-3=3/10.15

5.x/2-3=9/2

5.x/2=9/2+3

x/2=15/2:5

x=3/2.2

x=3

^^ungr hộ nha