You did say an approximate graph. Geogabra does not import items like this or I would have had a better approximation. But this one is good enough to get you going. The line is y = -x + 1.45. This graph is done on paint and then imported as an object into desmos. I got the equation just by guessing at it. You can shift the line around by changing the y intercept. You might be able to do a little better by experimenting with the slope. But you have to reproduce this on your graph so just start with y = -x and then keep moving it around until you get something that looks like what I have.
The time spent doing homework is 16 hours. That too is just an estimation, but it is close enough for your purposes.