Given that \(a\) and \(b\) are non-zero constants, and that the equations

\[\begin{align*} a^2x+aby&=a+4b\\ abx+b^2y&=a+b \end{align*}\]have an infinite number of solutions for \(x\) and \(y\), express \(a\) in terms of \(b\).

Given \(a\) and \(b\), what will the two equations look like when plotted as graphs on \(x\) and \(y\) axes? When will there be an infinite number of solutions for \(x\) and \(y\)?