Réponses

2014-06-04T12:59:38+02:00
On change de signe en passant le signe =

A) x+5 = 25
x=25-5
x=5

B) 6+y=-5
y=-5-6
y=-11

C) -6 + a= 7
a=7+6
a=13

D) t-12 = -7
t=-7+12
t=5
2014-06-04T13:14:54+02:00
A) x+5= 25
x +5 -5= 25 -5
x= 20

B) 6+y= -5
6 +y -6= -5 -6
y= -11

C= -6 +a= 7
-6 +a +6= 7+6
a= 13

D) t -12= -7
t -12 +12= -7 +12
t= 5