Frederick took out a 20-year loan for $70,000 at an APR of 2.2%, compounded monthly. Approximately how much would he save if he paid it off 9 years early?

$38,645.7208

Step-by-step explanation:

Given that

Principal = $70,000

Time = 20 years

Rate = 2.2%

The calculation of the amount of saving is shown below:-

A = Future amount

P = Principal amount  

0.001833333

t = 20 years which is equals to 240 months

= $108,645.7208

And, the loan amount for 20 years is $70,000

So,

He would save by paying off 9 years early is

= $108,645.7208  - $70,000

= $38,645.7208

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this