Answer:
Explanation:
The question is slightly ambiguous. The problem is, do you find the first 40 hours using 10x and then the second equation using x >40. I don't think so, but it should be made clear. It turns out that the first 40 hours does equal 400 so that you can use the second expression with no worries.
w(53) = 15(53 - 40) + 400
w(53) = 15(13) + 400
w(53) = 195 + 400
w(53) = 595