Abi and Barbara went shopping. After Abi spent $57
s, Barbara had 5 times as much as Abi. If Abi had $21
s more than Barbara at first,
- Express the amount of money that Abi had at first in terms of s.
- If s = 18, find the amount of money that the two lady had left after shopping.
|
Abi |
Barbara |
Before |
1 u + $57s |
5 u |
Change |
- $57s |
|
After |
1 u |
5 u |
(a)
1 u + 57
s = 5 u + 21
s5 u - 1 u = 57
s - 21
s4 u = 57
s - 21
s = 36
s1 u = 36
s ÷ 4 = 9
s Abi's amount at first
= 1 u + 57
s = 9
s + 57
s = $66
s (b)
1 u + 5 u = 6 u
6 u = 6 x 9
s = 54
s Amount the two lady had left
= 54 x 18
= $972
Answer(s): (a) $66
s; (b) $972