Question

Efectuati calculele :
1) (x+1)totul la a2a -x(x+5)
2) x(x+4) - (x+2)totul la a2a
3) x-3(x+3) - (x-2)totul la a2a

Answer 1

$a).(x+1)^2-x(x+5)=x^2+2 \cdot x \cdot 1+1^2-x^2-5x= \\ =x^2+2x+1-x^2-5x=-3x+1 \\ b).x(x+4)-(x+2)^2=x^2+4x-(x^2+2 \cdot x \cdot 2+2^2)= \\ =x^2+4x-(x^2+4x+4)=x^2+4x-x^2-4x-4=-4 \\ c).x-3(x+3)-(x-2)^2=x-3x-9-(x^2-2 \cdot x \cdot 2+2^2)= \\ =x-3x-9-(x^2-4x+4)=x-3x-9-x^2+4x-4= \\ =-x^2+2x-13$