x*x + 3x - 5 = 0
So x*x = 5 - 3x
Both Alpha and Beta are the roots of the equation,
>> Alpha square = 5 - 3*Alhpa
a = 5
b = -3
Alpha^3 = Alpha *(5 - 3*Alpha)
= 5*Alpha - 3*Alpha^2
= 5*Alpha - 3*(5 - 3*Alpha)
= 14*Alpha - 15
So Alpha^3 + 14*Beta = 14*Alpha - 15 + 14*Beta
Because (x-Alpha)*(x-Beta) = 0
So Alpha+Beta = -3
Alpha*Beta = -5
Alpha^3 + 14*Beta = 14*(-3) - 15 = -57
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