Question 150986
a boxing club charges nonmembers $4 per to workout and $10 per day for equipment rental. Members pay a yearly fee of $400 and a daily fee of 5$ for equipment rental. write and solve and equation to find out how many times you should use the gym to justify membership. 
;
Let x = no. of daily work-outs
:
Cost for non-members:
C = 4x + 10x
C = 14x
;
Cost for members,:
C = 5x + 400
:
At some point they will be equal, find that value for x then
14x = 5x + 400
14x - 5x = 400
9x = 400
x = {{{400/9}}}
x = 44.4
;
We can say that on the your 45th work-out the annual membership is best.
(Assuming it's done within one year, of course)
:
Non mem: 4(45) + 10(45) = $630
Member; 5(45) + 400 = $625