Bonjour;

L=

16z² +24z +9

IR

M=

6+15y -20y² -6+8y

= -20y² +23y

N=

5z -( -8z² -20z -6z -15)

= 5z +8z² +20z +6z +15

= 8z² +31z +15

P=

(12x -6) ( 3-x)

= 36x -12x² -18 +6x

= -12x² +42x -18

Explications étape par étape:

L=(4z+3)²

L=(4z+3)(4z+3)

L=16z²+12z+12z+9

L=16z²+24z+9

______

M=6+(5y-2)(3-4y)

M=6+15y-20y²-6+8y

M=-20y²+23y

______

N=5z-(4z+3)(-2z-5)

N=5z-(-8z²-20z-6z-15)

N=5z-(-8z²-26z-15)

N=8z²+31z+15

______

P=6(2x-1)(3-x)

P=6(6x-2x²-3+x)

P=6(-2x²+7x-3)

P=-12x²+42x-18