`7 : 9 = 7/9`
`8 : 11 = 8/11`
`2001 : 2008 = 2001/2008`
`a : 7 = a/7`
7:9 = 7/9
8:11 = 8/11
2001:2008 = 2001/2008
a:7 = a/7
7 : 9 = \(\dfrac{7}{9}\)
8 : 11 = \(\dfrac{8}{11}\)
2001 : 2008 = \(\dfrac{2001}{2008}\)
a : 7 = \(\dfrac{a}{7}\)
b : a+ c = \(\dfrac{b}{a}+c\)
c : ( a + b ) = \(\dfrac{c}{a+b}\)