bonjour
2 : 1 + 3 / ( 2 + 5/2 )
= 2 : 1 + 3 /( 4/2 + 5 /2 )
= 2 : 1 + 3 : 9/2
= 2 : 1 + 3 x 2/9
= 2 : 1 + 6 /9
= 2 / ( 9 + 6 ) / 9
= 2 : 15 /9
= 2 x 9 /15
= 18/15
= 6 /5
( 3 x + 2 ) / 3 - 5/2 = - 2 x /5 + 30/5
( 30 x + 20 ) /30 - 75/30 = - 12 x /30 + 180 /30
30 x + 12 x = 180 + 75
42 x = 255
x = 255/42 = 85/14
