ex1

1 d

2 b

3c

4 a

ex 2

1a et c

2 b et c

3 a et b

ex 3

a   -2x+5-4x+3= - 6x+8

b -5x+4x+3= - x +3

c   x²+x+3x+5x²+1=6x²+4x+1

d  6x²-3+5x-7x²+4-2x = -x² + 3x +1

e -2x*3x+2x+3x²-4 = - 6x²+3x²+2x-4= - 3x²+2x-4

f 2*(3x²)-(4x)*x+x² =6x² -4x²+x² = 3x²

ex4

a 3x+5x*(-2x)+x*2=3x -10x²+2x=5x -10 x²

b 2+3*4-x-x =2+12-2x=14 - 2x

c - x*-x +(-x)*x =x²-x²=0

d -3*2+(x*5)*3+x*2x= - 6 +15x+2x²