Algebra one, word equation

Question

Jane and Sophia went to the corner store where packages of gum cost 85 cents each and candy bars cost 60 cents each. They spent $15 and bought 4 more packages of gum than candy bars. How many packages of gum did they buy?

Answer 1

Let g be the number of packs of gum purchased; c be the number of candy bars purchased, then:

g = c +4

Money spent on gum is the number of packs (g) times the unit cost ($0.85) or:

0.85g

Money spent on candy bars is the number of bars (c) times the unit cost ($0.65) or:

0.60c

Total spent for gum and candy bars is: $15.00, so:

0.85g + 0.60c = 15

Substituting the value above for g:

0.85(c + 4) + 0.60c = 15

0.85c + 3.4 + 0.60c = 15

1.45c + 3.4 = 15

1.45c = 11.6

c = 8

And:

g = c + 4

g = 8 + 4

g = 12

Answer 2

.85g + .60c = 15

g=4+c

.85(4+c)+.6c = 15

3.4 + 1.45c = 15

1.45c = 11.6

c = 11.6/1.45 = 1160/145= 232/29= 8 candy bars

g = 12 gum packages