Sagot :
Hello,
5x = 3
x = 3/5
5 + x = 3
x = 3 - 5
x = -2
7x - 4 = 5x + 10
7x - 5x = 10 + 4
2x = 14
x = 14/2 = 7
10 + 2x = 0
2x = 0 - 10
2x = -10
x = -10/2 = -5
(10 + 2x) + (8 - x) = 0
10 + 2x + 8 - x = 0
x + 18 = 0
x = 0 - 18 = -18
-3x = 9
x = -9/3 = -3
Réponse :
a) 5x = 3
5x/5 = 3/5
x = 3/5
b) 5 + x = 3
5 + x - 5 = 3 - 5
x = -2
c) 7x - 4 = 5x + 10
7x - 4 + 4 = 5x + 10 + 4
7x - 5x = 5x + 14 - 5x
2x = 14
2x / 2 = 14 / 2
x = 7
d) 10 + 2x = 0
10 + 2x - 10 = 0 - 10
2x / 2 = -10 / 2
x = -5
e) (10+2x) + (8-x) = 0
10 + 2x + 8 - x = 0
10 + 2x + 8 - x - 10 - 8 = -10 - 8
x = -18
f) -3x = 9
-3x / -3 = 9/-3
x = -3
