[tex]\frac{6}{8}[/tex]
let x be the unknown value in the ratio, hence
[tex]\frac{6}{x}[/tex] = [tex]\frac{9}{12}[/tex] ( cross- multiply )
9x = 72 ( divide both sides by 9 )
x = 8
thus [tex]\frac{6}{8}[/tex] = [tex]\frac{9}{12}[/tex]