The domain of this equation is the lowest x value to the highest x value. For example: lowest is -4 and highest is 3. You would write it as [-4,3]
For this equation, the domain is (-infinity,infinity) because there is no lowest or highest x value.
All you have to do is put the walking amount in for w and basketball in for b. Do it for all of these, if it is less than 400 or greater than 600, it is not a solution.
(4 x 40) + (5 x 40) = 360 so reject because it is less than 400.
I'll let you do the rest.
