Answer:
B
Step-by-step explanation:
B
You start at 510
So 13 months is 560
14 is 610
15 is 660
16 is 710
17 is 760
18 is 810
Answer:
y=-3
Step-by-step explanation:
"varying directly" means there is only a factor between x and y, i.e.:
y = k·x
so k = y/x = -1/3
so if x=9, y = -1/3·9 = -3
