Réponses

2014-06-01T18:12:26+02:00
A) 2x + 1 = 5x - 5
2x + 1 - 2x = 5x - 5 - 2x
1 =  3x - 5
1 + 5 = 3x - 5 + 5
 \frac{6}{3}  \frac{3x}{3}
2 = x

b ) 4y - 12 = 18y + 48
4y - 12 - 4y = 18y + 48 - 4y
-12 =14y + 48
- 12 - 48 = 14y + 48 - 48
 \frac{-60}{14}  \frac{14y}{14}
 \frac{- 30}{7} = y
2014-06-01T18:21:08+02:00
a)
2x+1=5x-5
2x+1-1-5x=5x-5-5x-1
-3x=-6
x=-6/-3
x=2

b)
4y-12=18y+48
4y-12+12-18y=18y+48-18y+12
-14y=60
y=60/-14
y=30/-7

voilà :)