Luis had $160 less than Fred. If Fred spends $70 and Luis's mother gave Luis $450, Fred will have
15 as much money as Luis. How much money did Luis and Fred have?
| |
Make p the same
(1)x5 = (3) |
Luis
(1) |
Fred
(2) |
| Before |
5 u |
1 u |
1 u + 160 |
| Change |
- 350 |
- 70 |
+ 450 |
| After |
5 p |
1 p |
5 p |
Since Luis had $160 less than Fred, this means Fred had $160 more than Luis.
1 u - 70 = 1 p --- (1)
1 u + 160 + 450 = 5 p
1 u + 610 =
5 p --- (2)
Make p the same.
(1)
x5
5 u - 350 =
5 p --- (3)
(3) = (2)
5 u - 350 = 1 u + 610
5 u - 1 u = 610 + 350
4 u = 960
1 u = 960 ÷ 4 = 240
Total amount that Luis and Fred had
= 1 u + 1 u + 160
= 2 u + 160
= 2 x 240 + 160
= 480 + 160
= $640
Answer(s): $640
