bonjour j ai 1 devoir en maths mais je n y arrive pas pouriez vous m aidez s il vous plaît merci.

a =  1 -(1/3 +1/4) =  1 -( 4/12+3/12) = 1 - (7/12) =1-7/12 = 12/12-7/12 = 5/12

b = 1 -( 1/3+1/6+1/9) = 1 -( 6/18+3/18+2/18) 1 - 11/18 = 18/18-11/18 = 7/18

c = -4/3 -(5/6 -1/4) =  -4/3 -( 10/12-3/12) = -4/3 -7/12 = -11/12

d = 1/5 -(-1/15+3/25) +2/3 = 1/5 -(-8/100+12/100) +2/3 = 1/5 -4/100+2/3 = 20/100-4/100+2/3 = 16/100+2/3 = 4/25+2/3 = 12/75 +50/75 = 62/75