bonjour,
= 7/6 + 2/9
= (7*3)/ (6*3) + (2*2)/ (9*2)
= 21/18 + 4/18
= 25/18
B= 7/5 - 6/15
= 21/15 -6/15
(on a multiplié par 3)
= 15/15 = 1
C= 36/45 × 5/8
= (36*5) /(45*8)
=180/360 = 18/36= 1/2
D= 3/4 ÷ 12/10
= 3/4 * 10/12
=(3*10) / ( 4*12)
=30/48 = 15/24 = 5/8