V 5x + V ( 14 - x ) = 8
( V 5x + V ( 14 - x ))^2 = 8^2
5x + 14 - x + 2 V ( 5x( 14 - x )) = 64
64 - 14 - 4x = 2V( 5x( 14 - X ))
50 - 4x = 2V( 5x( 14 - X ))
2( 25 - 2x ) = 2V( 5x( 14 - X ))
25 - 2x = V( 5x( 14 - X ))
( 25 - 2x )^2 = ( V (5x( 14 - X ))
625 - 100x + 4x^2 = 70x - 5x^2
9x^2 - 170x + 625 = 0
D = 28900 - 22500 = 6400 = 80^2
X1 = ( 170 + 80 ) : 18 = 250/18 = 125/9 = 13 8/9
X2 = ( 170 - 80 ) : 18 = 5
ОДЗ
5х >= 0 ; Х >= 0
14 - Х >= 0 ; Х <= 14 <br>Ответ 13 8/9 ; 5