if alpha and beta are the zeroes of 3x2-2x-21,find the value of alpha cube and beeta cube
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=3x²-2x-21
=3x²-(9-7)x-21
=3x²-9x+7x-21
=3x(x-3)+7(x-3)
=(3x+7)(x-3)
3x+7=0
x=-7/3
α=-7/3
x-3=0
x=3
β=3
=α³
=(-7/3)³
=(-343/9)
=β³
=(3)³
=27
=3x²-(9-7)x-21
=3x²-9x+7x-21
=3x(x-3)+7(x-3)
=(3x+7)(x-3)
3x+7=0
x=-7/3
α=-7/3
x-3=0
x=3
β=3
=α³
=(-7/3)³
=(-343/9)
=β³
=(3)³
=27
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