bonjour

a) 3/7 + 7/3 = 9/21 + 49/21 = 58/21

b)  9/2 - 1/5 = 45/10 - 2/10 = 43/10

c)  2 ( 2/3 + 4) = 2 ( 2/3 + 12/3) = 2 * 14/3 = 28/3

d) 7 /36 : - 7 = 7/36 * - 1/7 = -  7/252 = - 1/36

e) ( 3/4 + 2/5) ² = ( 15/20 + 8/20) ² = (23/20)² = 529/400