Diagnostic Test 2

For the linear function $f$, the graph of $y = f(x)$ in the $xy$-plane is defined by the equation $2x + 5y = 20$. What is the $y$-intercept of the graph of $f$?

What is the sum of the solutions to the given equation?

$$ x^2 - 12x + 20 = 0 $$