bonjour;

18/8 = (9*2)/(4*2) =  9/4

9/12 = (3*3)/( 3*4) =  3/4

22/33 = (2*11)/( 3/11) = 2/3

35/28 = (7*5)/ (7*4) = 5/4

16/4 = (4*4)/ (4*1 ) = 4

4/16 = ( 4*1)/'(4*4) = 1/4

45/20 = (5*9) /( 5*4) = 9/4

20/500 = ( 5*2 *2)/ ( 5*2* 50)= 2/50 =( 2*1) /( 2*25) = 1/25