aide svp pourses deux ex ses pour demain merci en avence

Exercice 51
A) 2/3 + 5/3 * 4/7 = 2/3 + 20/21 = 14/21 + 20/21 = 34/21
B) 1/5 - 7/5 * 2/3 = 1/5 - 14/15 = 3/15 - 4/15 = -1/15
C) 7/30 - 4/3 : 5/2 = 7/30 - 4/3 * 2/5 = 7/30 - 8/15 = 7/30 - 16/30 = -9/30 = -3/10
D) (4 - 1/3) + 5/4 = (12/3 - 1/3) + 5/4 = 11/3 +5/4 = 44/12 + 15/12 = 59/12