The polynomial $ax^3 - 5x^2 + bx + 9$, where $a$ and $b$ are constants, is represented by $p(x)$. It is stated that $(2x + 3)$ is a factor of $p(x)$, and that dividing $p(x)$ by $(x + 1)$ leaves a remainder of $8$.
(a(i))[5]
Find $a$ and $b$.
(a(ii))[3]
With these values of $a$ and $b$, factorise $p(x)$ fully.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Substitute $x=-\frac32$, then equate the result to zero” …