slope =(y2-y1)/(x2-x1)
m=(-1-5)/(1--1)
m=-6/2
m=-3
y-y1=m(x-x1) point slope form
y-5 = -3 (x--1)
y-5 = -3 (x+1)
distribute
y-5 = -3x -3
add 5 to each side
y = -3x+2
Choice D
You can figure out the answer by doing this:
8% = 2300/x
and do the same for the second one
(and solve)
For one moth it would be....

$57.00 In total but im not sure if this is correct so if you could make sure please.
Im just about to work one out for you and you just do the same on the rest