David had $38.30 more than Tommy. After Tommy had spent
23 of his money, David had $68.90 more than Tommy. How much money did David have at first?
| |
David |
Tommy |
More |
| Before |
3 u + $38.30 |
3 u |
$38.30 |
| Change |
|
- 2 u |
|
| After |
3 u + $38.30 |
1 u |
2 u + $38.30 |
David had $68.90 more than Tommy in the end.
3 u + 38.30 - 1 u = 68.90
2 u + 38.30 = 68.90
2 u = 68.90 - 38.30
2 u = 30.60
1 u = 30.60 ÷ 2 = 15.30
Amount that David had at first
= 3 u + 38.30
= 3 x 15.30 + 38.30
= 45.90 + 38.30
= $84.20
Answer(s): $84.20
