Answer:
Quentin made a total of 4 shots
Explanation:
The complete question is as follows;
Quentin was challenged to a half-court shooting completion. For every half-court shot he makes, he will earn 20 points. For each half-court shot he misses, he will lose five points. After 20 half-court shots, Quentin has zero points. How many half-court shots did he make?
Now let's answer;
Let the number of shot he makes be x and the number of shot he misses be y
For every shot made, we have +20, for every shot missed, we have -5
Firstly we know that adding both numbers would give 20.
Mathematically;
x + y = 20 (i)
Now, we add the number of points he made to the number of points he missed to give a total of 0
Mathematically, that would be;
+20x -5y = 0 (ii)
from i, y = 20-x
Substitute this in ii
20x -5(20-x) = 0
20x - 100 + 5x = 0
25x = 100
x = 100/25
x = 4
This means that he made 4 shots