Answer: he collected 22 quarters and 8 fifty-cent pieces
Step-by-step explanation:
Given;
The total amount of money he is to collect is;
A = 20 - 10.50 = $9.50
Let x represent the number of quarter he collected.
Then the number of fifty-cent pieces he collected will be; 30-x
Therefore we can represent it with the equation below;
0.25x + 0.50(30-x) = 9.50
0.25x + 15 - 0.50x = 9.50
0.25x = 15-9.50
x = (15-9.50)/0.25
x = 5.50/0.25
x = 22
The number of fifty-cent is equal to;
30-x = 30-22 = 8
Therefore, he collected 22 quarters and 8 fifty-cent pieces