(a(i))[2]
Find $C$ for the values $x=5$ and $y=8$.
(a(ii))[2]
Find the positive value of $y$ given that $C=15$ and $x=2.4$.
(b)[3]
Write as a single fraction in its simplest form: $\frac{4}{x-1}-\frac{3}{2x+5}$.
(c)[3]
Expand and simplify the expression $(2x+3)(4-x)^2$.
(d)[3]
Simplify $\left(\dfrac{y^8}{16x^{16}}\right)^{-\frac{3}{4}}$.