This right answer is D.
because -65 divided by -13 is 5

Substitute this into the parabolic equation,

We're told the line
intersects
twice, which means the quadratic above has two distinct real solutions. Its discriminant must then be positive, so we know

We can tell from the quadratic equation that
has its vertex at the point (3, 6). Also, note that

and

so the furthest to the right that
extends is the point (5, 2). The line
passes through this point for
. For any value of
, the line
passes through
either only once, or not at all.
So
; in set notation,

Yellow:blue is a ratio of 2:3, meaning that 2/5 of the desired mixture is yellow. From this, you need to find how much yellow is necessary for 20 ounces. Well, 2/5 of the 20 ounces will be yellow paint, while the other 3/5 will be blue. So she will need 8 ounces of yellow paint to get 20 ounces of the desired mixture. Hope this helps! :)