Bonjour,
1) pour x=2,
À= 5*2+3(4*2-5)^2
= 10+3(8-5)^2
= 13(3)^2
= 37
2) A= 5x+3(4x-5)^2
= 5x +3[(4x)^2-2*4x*5+5^2]
= 5x+3[16x^2-40x+25]
= 5x +3*16x^2+3*-40x+3*25
= 5x+ 48x^2-120x+75
= 48x^2-115x+75
Vérification pour x=2
À= 48*2^2-115*2+75
= 37
3) pour x=2
B= 10*2^2-(2*2+3)^2
= 10*4-(4+3)^2
= 40-49
= -9
4) b= 10x^2 -(2x+3)^2
= 10x^2 - [(2x)^2+2*2x*3+3^2]
= 10x^2 - [4x^2+12x+9]
= 10x^2 -4x^2-12x-9
=6x^2-12x-9
Vérification pour x =2
B = 10*2^2-(2*2+3)^2
= 40-49
= -9
