Сократите дробь. (3a^2-11a-4)/(a^2-16)

Question

Сократите дробь.
(3a^2-11a-4)/(a^2-16)

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Answer 1

1) 3a² - 11a - 4 = 3( a + 1/3 )( a - 4 ) = ( 3a + 1 )( a - 4 )
D = 121 + 48 = 169 = 13²
a1 = ( 11 + 13 ) : 6 = 4 
a2 = ( 11 - 13 ) : 6 = - 1/3 
2) a^2 - 16 = ( a - 4 )( a + 4 )
3) (( 3a + 1 )( a - 4 )) / ( ( a - 4 )( a + 4 )) = ( 3a + 1 ) / ( a + 4 )