Answer:
# of questions : y = -x + 19
Explanation:
if ur only wanting the equation for the number of questions on the test, then it would be : x + y = 19......y = -x + 19 in slope intercept form.
and if u were wanting the number of points, then it would be :
5x + 10y = 100.....10y = -5x + 100.....y = -1/2x + 10. in slope intercept form