Effectuer les opération suivantes, simplifier le résultat si possible. A= 1 + 13/7          B=4 - 17/3              C=3/4 - 7/13

A= 1 + 13/7
A= 7/7 + 13/7
A= (7 + 13)/7
A= 20/7

B= 4 - 17/3
B= 12/3 - 17/3
B= (12 - 17)/3
B= - 5/3

C= 3/4 - 7/13
C= (3 * 13)/(4 * 13) - (7 * 4)/(13 * 4)
C= 39/52 - 28/52
C= 11/52

A = 1 + 13/7
A = 1 x 7 / 1 x 7 + 13/7
A = 7/7 + 13/7
A = 20/7

B = 4 - 17/3
B = 4 x 3 / 1 x 3 - 17/3
B = 12/3 - 17/3
B = - 5/3

C = 3/4 - 7/13
C = 3 x 13 / 4 x 13 - 7 x 4 / 13 x 4
C = 39/52 - 28/52
C = 11/52