Bonjour aidez moi silvouplais :) (1/4 - 1/5) x (7/1 + 37/9 ) = 2/3 + 1/6 : 2 - 1/2 = 3/4 + 1/2 x ( 2/3 - 1 ) =

= ( 1 / 4  - 1 / 5 ) x ( 7 / 1 + 37 / 9 )
= ( 5 / 20 - 4 / 20 ) x ( 63 / 9 + 37 / 9 )
= 1 / 20 x 100 / 9
= 100 / 180
= 5 / 9

= 2 / 3 + 1 / 6 : 2 - 1 / 2
= 2 / 3 + 1 / 12 - 1 / 2
= 8 / 12 + 1 / 12 - 6 / 12
= 9 / 12 - 6 / 12
= 3 / 12
= 1 / 4

= 3 / 4 + 1 / 2 x ( 2 / 3 - 1 )
= 3 / 4 + 1 / 2 x ( - 1 / 3 )
= 3 / 4 + ( - 1 / 6 )
= 18 / 24 - 4 / 24
= 14 / 24
= 7 / 12