Answer:
k = 3.
Step-by-step explanation:
If they are collinear the slope of AB = the slope of BC, so :-
(0- (-2)) / (2 - 0) = (k - 0) / (5 - 2)
2/2 = k/3
1 = k/3
k = 3.
It's 15 because
3 groups and 5 people in each group
and becomes 15
I HOPE THIS HELPS
For #2, the proportion would be .40/.25 and x/15, then you would cross multiply to find x. and for #3 the proportion would be 15/6 and 75/x and again you would cross multiply to find x. (: