Bonjour
A = 5/6 - 7/18 + 5/2
A = (5 x 3) / (6 x 3) - 7/18 + (5 x 9) / (2 x 9)
A = 15/18 - 7/18 + 45/18
A = 60/18 - 7/18
A = 53/18
B = 2/3 + 5/3 ÷ 15/21
B = (2x 15) / (3 x 15) + 5/3 x 21/15
B = 30/45 + 105/45
B = 135/45
B = (45 x 3) / (45 x 1)
B = 3.