(a)[5]
Determine the values of $a$ and $b$.
(b)[4]
Hence factorise $p(x)$, and find the exact roots of the equation $p(3x) = 0$.
Mathematics 9709 · AS & A Level · Algebra
Algebra — practice question
The polynomial $p(x)$ is given by $p(x) = 6x^3 + ax^2 + bx - 20$, where $a$ and $b$ are constants. It is stated that $(x + 2)$ is a factor of $p(x)$ and that dividing $p(x)$ by $(x + 1)$ leaves remainder $-11$.