Question

Efectuați:
$\frac{X^{2} }{X+9} - \frac{81}{X+9}$
​

Answer 1

$\frac{ {x}^{2} }{x + 9} - \frac{81}{x + 9} = \frac{ {x}^{2} - 81 }{x + 9} = \\ = \frac{ {x}^{2} - {9}^{2} }{x + 9} = \\ \\ = \color{red} {a}^{2} - {b}^{2} = ( a-b ) \times ( a+b ) \\ \\ = \frac{(x - 9) \times (x + 9)}{x + 9} = x - 9$

simplificam prin taiere (x + 9) cu (x +9)

…ᘛ⁐̤ᕐᐷฅ^•ﻌ•^ฅฅ^•ﻌ•^ฅ