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a fost răspuns

(x+3)*(x-3)+2x=(x+4)²+5

Răspuns :

x la a doua - 9+2x= x+ 8x+16+5= x la a doua + 10x+12
(x+3)(x-3)+2x=(x+4)²+5
x²-9+2x=x²+8x+16+5
x²+2x-9=x²+8x+21
2x-8x=21+9
-6x=30 ⇒x=-5