1ere serie
c)=(3+2y)x(3-2y)+(y-3/4)^2
=9-4y^2 + y^2 -3/4 y +9/16
=153/16 -3y^2 -3/2 y
d)=a^2 /9 +4/5a -(9a^2 -15a +25/4)
=80/9 a^2 +79/5 a -481/100
e)=64-81y^2 -6(y^2 -8y +16)
=64-81y^2 -6y^2 +48y -96
=-32-87y^2 +48y
f)=x*3x*(4+x^2)
= 3x^2 +(4+x^2)
=12x^2 +3x^4
