Bonjour,
Exercice 1
1. A=(2x-3)(-3x+5)
A=-6x²+10x+9x-15
A=-6x²+19x-15
B=3(5x-7)-5(2x+4)
B=15x-21-10x-20
B=5x-41
2. C=18x-45
C=9*2x-9*5
C=9(2x-5)
D=6x³-15x²+12x
D=3x*2x²-5x*3x+3x*4
D=3x(2x²-5x+4)
Exercice 2
1. (x+1)(x+3)
2. x*(x+3)/2
3. A(x)=(x+1)(x+3)-x*(x+3)/2-3*(x+1)