A parabola $ax^2+bx+c$ contains the points $(-1,0)$, $(0,5)$, and $(5,0)$. Find the value $100a+10b+c$.

Because we are given both the roots of the quadratic, we can narrow the equation down to $y = a(x+1)(x-5)$

Now, think about how we can use the remaining coordinate (0,5) to solve for a...

Now that you know the quadratic, I assume you can take it from here