Answer:
In order to justify membership she would have to use the gym for 45 days
Explanation:
Express the total amount for a given number of days to use the gym for nonmembers;
T=WD+ED
where;
T=total amount for nonmembers
W=workout charges per day
D=number of days
E=equipment charges per day
In our case;
T=unknown
W=$4
D=unknown=d
E=$10
replacing;
T=(4×d)+(10×d)
T=4 d+10 d
T=14 d...equation
Express the total amount for a given number of days to use the gym for members;
T=S+ED
where;
T=total amount for members
S=yearly standing fee
D=number of days
E=equipment charges per day
In our case;
T=unknown
S=$400
E=$5
D=unknown=d
replacing;
T=400+(5×d)
T=400+5 d.....equation 2
To justify membership, equate equation 1 to equation 2
14 d=400+5 d
14 d-5 d=400
9 d=400
d=400/9
d=44.44=45
In order to justify membership she would have to use the gym for 45 days