Question

Х^2-(9-х)^2>-2х решите неравенство

Answer 1

$20x-81\ \textgreater \ 0$
$20x\ \textgreater \ 81$
$x\ \textgreater \ \frac{81}{20}$
©UmnyjChuvak

Answer 2

x²-(9-x)²>-2x
x²-81+18x-x²+2x>0
20x>81
x>81/20
x>4.05