for you need to find graphically where cuts the x-axis. It seems to cut through the points
With the next question you have to consider where and intersect each other.
They do not intersectat a value that is clearly defined on your graph but you can conclude that the solution lies on
To get exact values in can solve this kind of equations using a little algebra, solve for x
moving everything to one side
then completing the square
Completing the square - Wikipedia, the free encyclopedia