a = - 1 , b = 1/3 et c = 2/5
A = a/b + c
A = - 1 : 1/3 + 2/5
A =- 1 * 3 + 2/5
A =- 3 + 2/5
A = - 15/5 + 2/5 = - 13/5
pour a = 1/2 , b = 5/4 et c = 3/4
B = a + b/c
B = 1/2 + 5/4 : 3/4
B = 1/2 + 5/4 * 4/3
B = 1/2 + 20/12
B = 6/12 + 20/12 = 26/12 = 13/6
C = a/b + c
C = 1/2 : 5/4 + 3/4
C = 1/2 * 4/5 + 3/4
C = 4/10 + 3/4
C = 8/20 + 15/20
C = 23/20