Explanation:
I believe we are expected to solve for the number of lawns she would mow before she could make profit
let the cost be C
and let the price be P
and let the number of lawn be x
C=$450----------1
P=6+20x---------2
equating 1 and 2 we can find x
450=6+20x
450-6=20x
444=20x
x=444/20
x=22.2
therefore for her to break even and start making profit she need to mow 22.2 lawns and above