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:
.
Yes it is congruent to5x-1
% increase = 100 - 85
--------- * 100
85
= 17.65
= 18 % to nearest per cent
Its wrong for x = 2
y = (3/4) * 2^2 = 3 (NOT 4)
Answer:
The measure of one angle of a regular convex 20-gon is 162°
Step-by-step explanation:
* Lets explain how to solve the problem
- A convex polygon is a polygon with all the measures of its interior
angles less than 180°
- In any polygon the number of its angles equal the number of its sides
- A regular polygon is a polygon that is all angles are equal in measure
and all sides are equal in length
- The rule of the measure of an angle of a regular polygon is
, where m is the measure of each interior
angle in the polygon and n is the numbers of the sides or the angles
of the polygon
* Lets solve the problem
- The polygon is convex polygon of 20 sides (20 angles)
- The polygon is regular polygon
∵ The number of the sides of the polygon is 20 sides
∴ n = 20
∵ The polygon is regular
∴ All angles are equal in measures
∵ The measure of each angle is 
∴
∴ 
∴ 
∴ m = 162
∴ The measure of one angle of a regular convex 20-gon is 162°