bill=cost of service+ (15% of cost of service)+data fee
bill=61
data fee=9.25
percent means parts out of 100 so
15%=15/100=0.15
'of' means multiply
c=cost
tax=0.15 times c or 0.15c
61=1c+0.15c+9.25
add like terms
61=1.15c+9.25
subtract 9.25 from both sides
51.75=1.15c
divide both sides by 1.15
45=c
the cost of the phone bill is $45