Bonjour,
Résoudre les équations suivantes et, si possible, donner les solutions en écriture fractionnaire simplifiée:
a.
-25x + 7 = -43
-25x + 7 - 7 = -43 - 7
-25x = -50
25x = 50
x = 50/25
x = 2/1 = 2
b.
5a - 7 = -2
5a - 7 + 7 = -2 + 7
5a = 5
a = 5/5 = 1
c.
12y - 8 = 4y + 2
12y - 8 + 8 = 4y + 2 + 8
12y = 4y + 10
12y - 4y = 4y + 10 - 4y
8y = 10
y = 10/8 = 1,25
d.
5(x - 2) = -3(x + 2)
5x - 10 = -3x - 6
5x - 10 + 10 = -3x - 6 + 10
5x = -3x + 4
5x + 3x = -3x + 4 + 3x
8x = 4
x = 4/8
x = 1/2 = 0,5
e.
7(x - 6) = 4 - 3(x + 2)
7x - 42 = 4 - (3x + 6)
7x - 42 = 4 - 3x - 6
7x - 42 = -3x - 2
7x - 42 + 42 = -3x - 2 + 42
7x = -3x + 40
7x + 3x = -3x + 40 + 3x
10x = 40
x = 40/10
x = 4/10 = 0,4
✅
Bonne journée.
