Question

Find the value of a in the polynomial p(x)=2x³+ax²-8x+a, when it is given that it is completely divisible by x-3. Hence factorise the polynomial.

Answer 1

since it is completely divisible by (x-3), p(3) = 0.
2*3^3+3^2a-8*3+a=0
or, 54-24+9a+a=0
or, 10a = -30
or, a = -3 ,,

:)