Question

Rezolvați ecuația :
2x (x+5)-17=(x+2) la a2a +(x-3)(x+3)

Answer 1

$\displaystyle 2x(x+5)-17=(x+2)^2+(x-3)(x+3) \\ 2x^2+10x-17=x^2+2 \cdot x \cdot 2+2^2+x^2-9 \\ 2x^2+10x-17=x^2+4x+4+x^2-9 \\ 2x^2+10x-x^2-4x-x^2=4-9+17 \\ 6x=12 \\ x= \frac{12}{6} \\ x=2$