Answer:
1st problem: b) 
2nd problem: c) 
Step-by-step explanation:
1st problem:
The formula/equation you want to use is:

where
t=number of years
A=amount he will owe in t years
P=principal (initial amount)
r=rate
n=number of times the interest is compounded per year t.
We are given:
P=2500
r=12%=.12
n=12 (since there are 12 months in a year and the interest is being compounded per month)

Time to clean up the inside of the ( ).


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2nd Problem:
Compounded continuously problems use base as e.

P is still the principal
r is still the rate
t is still the number of years
A is still the amount.
You are given:
P=2500
r=12%=.12
Let's plug that information in:
.
X+4x=35-20. 5x=35-20. 5x=15. X=3
<h2>○=> <u>Correct options</u> :</h2><h2>□

</h2><h2>□

</h2><h3><u>Steps to derive the correct options</u> :</h3>
Since two sides and one included angle is equal in △PQS and △PRS, we can conclude that they are congruent under the SAS congruence criterion.
Which means :
▪︎Angle S = Angle S
▪︎PS = PS
▪︎QS = RS
Given :
Measure of segment QS = 6n+3
Measure of segment RS = 4n+11
Thus :







Thus, the value of n = 4
Measure of segment QS :




Thus, measure of QS = 27
Measure of RS :




Measure of QR :


Thus :
▪︎QS = 27
▪︎RS = 27
▪︎QR = 54
Therefore, the correct options are :
▪︎(C) SR = 27
▪︎(D) QR = 54
I think the answer may be 291
Volume of the cube with side 4p = 4p x 4p x 4p = 64p³
Volume of the cube with side 2q² = 2q² x 2q² x 2q² = 8q⁶
Total Volume = 64p³ + 8q⁶
Total Volume = (4p)³ + (2q²)³
Total Volume = (4p + 2q²)( ( 4p)² - (4p)(2q²) + (2q²)²)
Total Volume = (4p + 2q²)( 16p² - 8pq² + 4q⁴)
Answer: (4p + 2q²)( 16p² - 8pq² + 4q⁴)