1st formula 2n + 3m = 280
2nd formula 2n + 5m = 320
rearrange 1st formula to equal n:
2n = -3m + 280
n = -3/2
m + 140
rearrange 2nd formula to equal n:
2n = -5m + 320
n = -5/2m + 160
so now you have
-3/2m + 140 = -5/2m + 160
Rearrange to become:
-3/2m + 5/2m = 160 - 140
m = 20
Now place 20 into the very 1st equation in place
of the letter m
2n + 3(20) = 280
2n + 60 = 280
2n = 220
n = 110
so it costs $110 per night, $20 per meal
