Question

Find all values of \(a\), \(b\), \(x\) and \(y\) that satisfy \[\begin{align*} a+b &= 1 \\ ax+by &= \frac{1}{3} \\ ax^2+by^2 &= \frac{1}{5} \\ ax^3+by^3 &= \frac{1}{7}. \end{align*}\]

[Hint: you may wish to start by multiplying the second equation by \(x+y\).]