Fabian saved $9 each day and Rachel saved $
i more than Fabian each day. After 6 weeks, they were still short of $31 to buy a stereo system.
- How much did the stereo system cost? Express your answer in terms of i.
- If i = $3, how much did the stereo system cost?
(a)
Amount Fabian saved per day = $9
Amount Rachel saved per day = $(9 +
i)
Total amount both saved per day
= 9 + 9 +
i = $(18 +
i)
Number of days in 6 weeks
= 6 x 7
= 42
Total both saved in 6 weeks
= 42(18 +
i)
= 42 x 18 + 42 x
i = $(756 + 42
i)
Cost of the stereo system
= 756 + 42
i + 31
= 756 + 31 + 42
i= $(787 + 42
i)
(b)
If
i = $3,
Cost of the stereo system
= 787 + 42 x 3
= 787 + 126
= $913
Answer(s): (a) $(787 + 42
i) or $(42
i + 787); (b) $913
