Răspuns :
A) (x+5)×(x-3)-(x-3)(x-5)+(x+1)(-x-3)=x²-3x+5x-15-(x²-5x-3x+15)-x²-3x-x-3=x²-3x+5x-15-(x²-8x+15)-x²-3x-x-3=-3x+5x-15-x²+8x-15-3x-x-3=6x²-33-x²= -x²+6x-33
b) (x+7)³ =x³+3x² * 7+3x * 7² +7³=x³+21x²+147x+343
c)(x+3)²+(x-3)²+(x-3)(x+3) =x²+6x+9+x²-6x+9+x²-9=3x²+9
d) (x-5) (x+9)=x² : x⁴
x²+9x-5x-45=x²⁻⁴
x²+4x-45=x⁻²
e)(x-1)²-(x+1)²-(x+1) (x-1)=(-2) * 2x-(x²-1)=-4x-x²+1
Succes
b) (x+7)³ =x³+3x² * 7+3x * 7² +7³=x³+21x²+147x+343
c)(x+3)²+(x-3)²+(x-3)(x+3) =x²+6x+9+x²-6x+9+x²-9=3x²+9
d) (x-5) (x+9)=x² : x⁴
x²+9x-5x-45=x²⁻⁴
x²+4x-45=x⁻²
e)(x-1)²-(x+1)²-(x+1) (x-1)=(-2) * 2x-(x²-1)=-4x-x²+1
Succes