Question

please solve this please
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Answer 1

Answer:

4) 0

5) 0

Step-by-step explanation:

4) a³ + 27 = a³ + 3³

= ( a + 3 ) ( a² - 3a + 3² )

= a ( a + 3 ) ( a - 3 + 9/a )

But we're given a + 9/a = 3, so the last factor is 0.

Therefore a³ + 27 = 0.

5) a/b + b/a = 1

=>  a² + b² = ab        [ multiplied everything by ab ]

=>  a² - ab + b² = 0

=> ( a + b ) ( a² - ab + b² ) = 0

=> a³ + b³ = 0