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

Răspuns :

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

[tex]\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} \\ \boxed{x=5} [/tex]