Réponse :
2.3
a. 3x=2x+5
3x-2x = 5
x=5
b. 4-5x=9x
-5x-9x=-4
-14x=-4
x=-4/-14= 2/7
c. 4x+2=x+11
4x-x=11-2
3x=9
x=9/3=3
d. 3x-7=-2x-9
3x+2x=-9+7
5x=-2
x=-2/5
e. 5x-1 = 7x-1
5x-7x=-1+1
-2x=0
x=0
f. 3x-2+x = 6+4x
3x + x - 4x = 6 + 2
4x - 4x = 8
0=8 impossible
2.4.
a. 4x=3/5
x = 3/5 * 1/4 = 3/20
b. 2/3x=7
x = 7 * 3/2 = 21/2
c. 6/5x = -7/11
x = -7/11 * 5/6 = -35/66
d. -7x = 4/-3
x = 4/-3 * -1/7 = 4/21
e. -3/2x = 5
x = 5/(-3/2) = 5*2/3 = 10/3
f. impossible à lire
2.5.
a. x²=6
b. 3x=33
c. 2x+6=0
d. 3x-6=9
2.6.
a. 12x=1 020
b. x+7=1,54
c. 99+2x=127 2x=127-99=28 x= 28/2=14
d.
Explications étape par étape :
