we know that in a cubic polynomial in form of
sum of the roots=-b/a =5/2
sum of the product of the roots taken two at a time=c/a =12/5
product of the roots=-d/a =2
the cubic polynomial is given by:-
x³-(sum of the roots)x²+(sum of the product of the roots taken two at a time)x+(product of the roots)
=>x³-(5/2)x²+(12/5)x-(2)
=>x³-5x²/2+12x/5-2