[tex]0,1(6)=\frac{16-1}{90} =\frac{15}{90} =\frac{1}{6}[/tex]
[tex]\frac{a}{b} =\frac{1}{6}[/tex]
[tex]b =6*a[/tex]
Inlocuim b in raportul cerut de problema si obtinem:
[tex]\frac{6*a+b}{21*a-b} =\frac{6*a+6*a}{21*a-6*a} =\frac{12*a}{15*a} =\frac{12}{15} =\frac{4}{5}[/tex]