Answer:
6/5
Step-by-step explanation:
Answer:
Q (2.5, -4)
Step-by-step explanation:
Let A (1, -5), C = (10, 1), find Q (x, y), so that AQ:QC = 1:5
AQ = (x - 1, y + 5)
QC = (10 - x, 1 - y)
AQ:QC = 1:5
so 5*AQ = QC
5(x - 1) = (10 - x)
5(y + 5) = 1 - y
Solve them:
5x - 5 = 10 - x
6x = 15
x = 15/6 = 2.5
5y + 25 = 1 - y
6y = -24
y = -24/6 = -4
Then answer is Q (2.5, -4)
Since two people take both courses, we can subtract two from 7, 8, and 21, giving us 5, 6, and 19.
Add 5 and 6 together to get 11. Since eleven students are in those two groups, we can answer this. The answer will be 11/19.