Rachel and Natalie went shopping. After Rachel spent $87
z, Natalie had 4 times as much as Rachel. If Rachel had $21
z more than Natalie at first,
- Express the amount of money that Rachel had at first in terms of z.
- If z = 36, find the amount of money that the two lady had left after shopping.
|
Rachel |
Natalie |
Before |
1 u + $87z |
4 u |
Change |
- $87z |
|
After |
1 u |
4 u |
(a)
1 u + 87
z = 4 u + 21
z4 u - 1 u = 87
z - 21
z3 u = 87
z - 21
z = 66
z1 u = 66
z ÷ 3 = 22
z Rachel's amount at first
= 1 u + 87
z = 22
z + 87
z = $109
z (b)
1 u + 4 u = 5 u
5 u = 5 x 22
z = 110
z Amount the two lady had left
= 110 x 36
= $3960
Answer(s): (a) $109
z; (b) $3960