What is the midpoint of a line segment whose endpoints are (-4,3) and (5,-6)?
.5,-4.5)
,-1.5)
,1.5)
.5,4.5)

Okay, so let's start with the labeling first:
(-4 = x1, 3 = y1) and (5 = x2, -6 = y2)

So now it's time to use the formula:

x Midpoint = (x1 + x2) / 2
y Midpoint = (y1 + y2) / 2

So then that would be:

x Midpoint = (-4 - 5) = (4 + 5) / 2 = 4.5
y Midpoint = (3 - -6) = (3 + 6) / 2 = 4.5

So therefore our answer for the midpoint would be:
(4.5, 4.5) which is D

This is the equation of compound interest where x is the number of years:
A=initial value x (1+ interest in %)^x
in our case: 1,000,000,000= 42 x (1+.41)^x
You solve x either with a calculator or with logarithm & you will find 49.44 years or almost 50 years. So it will reach the billion in 2050
Should you need further explanation do contact me