since we have 3x+4y, we want to maximize the x and y values
we want to get as far top right as possible
hmm, I'm thinking it might be on the line 3x+4y=240
let's test the boundaries
so the boundaries of that line are at (20,45) and (60,15)
at (20,45), the value is 240
at (60,15), the value is 240 as well
well, that doesn't work
so maybe it's somewhere between it
ok, so find the max value of 3x+4y=240
hold a sec,
the line is 3x+4y=240
so the max value is 240
the max value is 240