Réponses

2014-06-11T17:35:08+02:00
x-5=7
x-5+5=7+5
x=12

x+14=-15
x+14-14=-15-14
x=-29

x-(-6)=-12
x+6-6=-12-6
x=-18

voilà :)
2014-06-11T17:35:28+02:00
X-5 = 7
x = 7+5
x = 12

x+14 = -15
x = -15-14
x = -29

x-(-6) = -12
x+6 = -12
x = -12-6
x = -18