Have:

\(\dfrac{561}{143}\approx3,923\\ \dfrac{12}{13}\approx0,923\\ \dfrac{1463}{247}\approx5,923\)

3,923:0,923\(\approx4,25\)

5,923: 0,92\(\approx6,42\)

x is integer when 4,25<x<6,42

=>x=5