15 is the answer, I think.
Answer:
21 roads
Step-by-step explanation:
If each two cities are connected by a direct road, to find the number of roads we just need to solve a combination of 7 choose 2, that is, we need to find all pairs of two cities among the 7 cities:
Combination of 7 choose 2 = 7! / (5! * 2!) = 7*6/2 = 21
So there is a total of 21 roads on the island.
I would say infinitely many
Answer:
y - 5 = 6(x + 9)
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the line
Here m = 6 and (a, b) = (- 9, 5), thus
y - 5 = 6(x - (- 9)), that is
y - 5 = 6(x + 9)
