The roots of the equationx^2 - 2x + 7=0are alpha and beta. Without finding the value of alpha and beta explicitly, determine2B^3 - 3a^2 + 6(abeing alpha andBbeing beta)

i post it here as i feel that its a complex number question but i found this question from grade 9 where complex numbers have yet to be introduced (singapore)

really desperate to solve this question. the answer seem to be a clear cut integer instead of multiple answers in complex form.

by the way, this has to do with sum and product of roots