9x∧2-14y-14xy+9x
<span>при x=5/9.y=5/14
9(5/9)^2-14(5/14)-14(5/14)(5/9)+9(5/9)=5/9-5-5*5/9+5=20/9=2 2/9</span>
(a + b)^2 = 36, (a + b)^2 = (+-6)^2, a + b = +-6
a^2 - b^2 = 24 = (a + b)(a - b) ===> a - b = +-4
(a - b)^2 = (+-4)^2 = 16
Ответ. 16.
4с(с-30)=с(с+1)-с²
4с²-120с=с²+с-с²
4с²-120с-с=0
4с²-121с=0