Réponses

2014-06-02T18:09:19+02:00
5(3-a)-3(a-4) = 5(a+3)
15-5a-3a-4 = 5a+15
11-8a = 5a+15
8a+5a = 11-15
13a = -4
a = -4/3
2014-06-02T18:09:31+02:00
5(3-a)-3(a-4)  = 5(a+3)

15 - 5a - 3a + 12 = 5a + 15
27 - 8a = 5a + 15
27 - 15 = 5a + 8a
12 = 13a
a = 12/13
a = 0.92