Réponse:
A= 3x +18 - 2
=3x +16
B=4 + 6y - 6
=-2 +6y
C= 7 - x +8.2
= 15.5 - x
D=9x- 54 + 2x
= 11x - 54
F=x exposant 2 + 6x-x
= x exposant 2 + 5x
H= xy - 2x +xy
= 2xy - 2x
G= 2x exposant 2 + 2x - 4x exposant 2
= 2x exposant 2 + 2x
I= 3x exposant 2 + 12x - 6x exposant 2
= 3x exposant 2 + 12x.