If he has 6 friends they will all get 8 cards
See attached picture for answre
(x+4) + ((x-15)+4)= 41
2x-7= 41
2x= 48
x= 24
2250 + 6x = 16x
2250 = 16x - 6x
2250 = 10x
2250/10 = x
225 = x <=== they must sell 225 cameras to equal daily costs
if they increase production by 50.......x = 225 + 50 = 275
16(275) - 6(275) - 2250 = 4400 - 1650 - 2250 = 4400 - 3900 = 500.
Their daily profit would be $500.
