Sagot :
1 ni vraie ni fausse ça dépend de x
2. oui pour x = 2
3. 1) .x = 4 2) x = 0
3) soit le nombre (x + 3).2 +2x = 48 => 4x + 6 = 48 => x = 42/4 = 13
(x + 5 ) .3 + 2x = 115 => 5x + 15 = 115 => 5x = 100 => x = 20
7x+5= x+17
7x-x = 17-5
6x = 12
x= 12/6 = 2
3x+8 = 20
3x= 20-8
3x = 12
x = 12/3 = 4
2) 6(x+3)-12 = 6
6x+18 -12 =6
6x = 6+12-18
6x = 18-18
6x = 0
x = 0
3) (x+3)*2 = 2x+6
(2x+6)*2 = 4x+12
4x+12+2x = 48
6x = 48-12
6x = 36
x = 6
(x+5)*3 = 3x+15
3x+15+2x = 115
5x=115-15
5x = 100
x = 20