\(5.\left(x+1\right)=51\)

\(x+1=10,2\)

\(\Rightarrow x=9,2\)

\(b,75\%;368\%;543,2\%;1749,86\%\)

11/5;13/6;9/5;5/4;2/3;1/2

\(x+1,2.x=\dfrac{5}{6}\)

\(x.\left(1,2+1\right)=\dfrac{5}{6}\)

\(x.\dfrac{11}{5}=\dfrac{5}{6}\)

\(x=\dfrac{5}{6}.\dfrac{5}{11}\)

\(\Rightarrow x=\dfrac{25}{66}\)