V ( 11 + x ) = a ;
11 + x gt;= 0 ; x gt;= - 11
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a / 4 - ( 2 / a ) = 1/2 общий знаменатель 4а
( а^2 - 8 ) / 4а = 1/2
2( а^2 - 8 ) = 4а
2( а^2 - 8 - 2а ) = 0
а^2 - 2а - 8 = 0
D = 4 + 32 = 36 = 6^2
a1 = ( 2 + 6 ) : 2 = 4
a2 = ( 2 - 6 ) : 2 = - 2
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V ( 11 + x ) = 4
11 + x = 16
X = 5
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V ( 11 + x ) = - 2
11 + x = - 2
X = - 13 ( не подходит )
ОТВЕТ 5
Проверка
( V ( 11 + 5 ))/4 - ( 2/( V11 + 5 )) = 1/2
4/4 - ( 2/4 ) = 1/2
1 - ( 1/2 ) = 1/2
1/2 = 1/2