Answer:
20
Step-by-step explanation:
x^2+18x-160
If you put this into your calculator or desmos, you will get a parabola. You want to know the value of x when y=600. You can look at the table for the graph or scan to where y = 600. The value of x is 20 at that point.
To check you can plug 20 in for x. When you do that, y = 600.