Answer:
Sandra's speed was consistent and persistent she proved it by lining up the segments she placed on the graph and at what time as well.
You haven't provided the required roots, but I can tell you how to do this kind of exercises in general.
If the
coefficient is 1, i.e. the equation is written like
, then you can say the following about the coefficients b and c:
is the opposite of the sum of the roots
is the multiplication of the roots.
So, for example, if we want an equation whose roots are 4 and -2, we have:
So, the equation is 
If your roots are rational, you can work like this: suppose you want an equation with roots 3/4 and 1/2. You have:
And so the equation is

In order to have integer coefficients, you can multiply both sides of the equation by 8:

.86, 7/8, .9 is least to greatest