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bonjour

exercice 2

a = -4/9 +2/7 = -28/63 +18/63 = -10/63

b = -5/-9 x -18/ 35 = 5/9 x  -9*2/7*5 =  -2/7

c = 4 -2 x 29/7 = 4 - 58/7 = 28/7 -58/7 = -30/7

d = ( -10/7 +6/7) : 3/35 = - 4/7 x 35/3 = -140/21 = -20/3