Answer:
a. 
Step-by-step explanation:
The given equation is;

To solve by the x-intercept method we need to graph the corresponding function using a graphing calculator or software.
The corresponding function is

The solution to
is where the graph touches the x-axis.
We can see from the graph that; the x-intercepts are;
(-1,0),(3,0) and (6,0).
Therefore the real solutions are:

He needs one more quart. That is half of a gallon.
Answer:
Step-by-step explanation:
Its about 42.67