Answer:
A 5-pound of flour costs $4.80. For this bag of flour, what is the cost of flour per ounce? (1 pound = 16 ounces) a. $0.06.
Step-by-step explanation:
When x=-1:

Ok that gives us a little more information.
If we implicitly differentiate with respect to t, from the very start, then we can apply our product rule, ya?

The right side is zero, derivative of a constant is zero.
Where x' is dx/dt and y' is dy/dt.
From here, plug in all the stuff you know:
y' = -3
x = -1
y = 4
and solve for x'.
Hope that helps!
(0,2) represents the y intercept on the graph cause at that point it crosses the y axis