Question

Rezolvati-mi complet exercitiul urmator:

(x-5)X(x+5)-(x-3)la puterea a doua = x-9

Dau coroana

Answer 1

(x-5)(x+5) - (x-3)² = x-9
x² -25 -(x² -6x+9) = x-9
x² -25 -x² +6x -9 = x-9
6x -34 =x-9
6x-x = 34-9
5x = 25
x= 25 / 5
x=5

Answer 2

$\displaystyle (x-5)(x+5)-(x-3)^2=x-9 \\ x^2-25-(x^2-2 \cdot x \cdot 3+3^2)=x-9 \\ x^2-25-(x^2-6x+9)=x-9 \\ x^2-25-x^2+6x-9=x-9 \\ x^2-x^2+6x-x=-9+25+9 \\ 5x=25 \\ x= \frac{25}{5} \\ x=5$