(a)[3]
Determine $a$ and $b$ in terms of the constant $k$.
(b)[3]
If $a + b = 216$, determine the possible values of $k$.
Mathematics 9709 · AS & A Level · Quadratics
Quadratics — practice question
In the expansion of $(2x^2 + \frac{k^2}{x})^5$, let the coefficient of $x^4$ be $a$. In the expansion of $(2kx - 1)^4$, let the coefficient of $x^2$ be $b$.