Bonjour,
Ex 1
x= 2.5-7
x= -4.5
-5x-6x=1-3
-11x= -2 et x= 2/11
-5x+3x= -7
-2x=-7 et x= 7/2
-6x-10-x= 7
-7x = 7+10
x= -17/7
2)
3x=x+5
3x-x=5
2x=5
x=5/2
Ex 2
A= 6x-21
B= -5x+7x²
C= 81x-36x²+40-20x=> -36x²+61x+40
D= 4x²-12x+9
E= 9x²-121
F= 3x²-13x-64
Ex 3
1)
G= 40x²-29x+3
2)
G= (5x-3)(3x+2+5x-3)
G= (5x-3)(8x-1)
3)
5x-3=0 ou 8x-1=0
x= 3/5 x= 1/8
