Elijah had $130 less than Mark. If Mark spends $90 and Elijah's mother gave Elijah $650, Mark will have
14 as much money as Elijah. How much money did Elijah and Mark have?
| |
Make p the same
(1)x4 = (3) |
Elijah
(1) |
Mark
(2) |
| Before |
4 u |
1 u |
1 u + 130 |
| Change |
- 360 |
- 90 |
+ 650 |
| After |
4 p |
1 p |
4 p |
Since Elijah had $130 less than Mark, this means Mark had $130 more than Elijah.
1 u - 90 = 1 p --- (1)
1 u + 130 + 650 = 4 p
1 u + 780 =
4 p --- (2)
Make p the same.
(1)
x4
4 u - 360 =
4 p --- (3)
(3) = (2)
4 u - 360 = 1 u + 780
4 u - 1 u = 780 + 360
3 u = 1140
1 u = 1140 ÷ 3 = 380
Total amount that Elijah and Mark had
= 1 u + 1 u + 130
= 2 u + 130
= 2 x 380 + 130
= 760 + 130
= $890
Answer(s): $890
