Can someone me with this question?

Well as a cashier he earns 9$ an hour, so if he works 11 hours he will earn 99$ and he earns 10.75$ an hour because 129 divided by 12 is 10.75 and since he earns 10.75 for a grocery stocker he will earn 182.75 for working 17 hours. in total he earns 281.75$. 

Δ = 1 + 4*20 = 81
x' = (-1 + 9)/2 = 4
x'' = (-1 - 9)/2 = -5
4²  + 4 - 20 = 0
(-5)² - 5 - 20 = 0
Ok !