CPhill

P = 4864.77

r = interest rate  =  .039

n =  compoundings per year  =  2   [ twice per year ]

t = time =  2  [years] 

So we have

A  = 4864.77 [ 1 + .039/2]^(2* 2 )   = $5255.47 ⇒ "C"

Income =  Interest earned  - check fee - financial charge

1210 (.008)  -  21 (.10)  - 2.00   =  $5.58 ⇒ "B"

OK, NSS...I'm going to let you do this one

1. Add the night deposit to the opening balance

2. Total up  the checks....subtract this from 1

3. From 2...subtract the amount transferred to savings

This will be your ending balance....I'll double-check it if you want me to...

"D"

See here, NSS....https://www.investopedia.com/financial-edge/1111/3-easy-ways-to-improve-your-credit-score.aspx

We want to solve this

-0.06 x  + 8.3   >  -0.02x + 6.6     add -0.02x to both sides...subtract 8.3 from  both sides

-0.04x  > -1.7     divide both sides by  -0.04 ..... reverse the inequality sign

x < 42.5   [  after  42 checks are written Long's bank is cheaper than Fellow's bank ]

First one  ⇒  negative rate of change

Second one ⇒ positive rate of change

Third one ⇒ negative rate of change

Last one ⇒  positive rate of change

See my answer here : https://web2.0calc.com/questions/geometry-help_67

"y" =  180 - 131   = 49°   = the vertical angle to y at the bottom left of the top triangle

The angle supplemental to the 142° angle = 180 - 142  = 38°

So "w"  =  180 - 49 - 38  = 93°

By the interior angle theorem, the angle at the bottom right of the top triangle = 93 - 42  = 51°

So..  "t"  will =   180 - 49 - 51   =  80°

Look at the following graph : https://www.desmos.com/calculator/rfebje54mw

The first two constraints just tell us that we are in the first quadrant...we can ignore them

The x/y coordinates that maximize the objective function occur at the cornrer point (12,5)

So...the max value is

C  = 7(12) + 9(5)  =  84  + 45   =  129