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:
.
Answer:
Uneffected.
Step-by-step explanation:
The order of the numbers doesn't affect the product in multiplication problems.
For example, we need to multiply 2 × 10.
We can write it as : 2×5×2
2×(5×2) = 2×10 = 20
Also,
(2×5)×2 = 10×2 = 20
Hence, it will remain unaffected when we multiply numbers.
Answer:

Step-by-step explanation:
Given: 
To solve this equation, we need to isolate
on one side of the equation algebraically. I see that we have like terms, but they are on opposite sides of the equal sign. Let's add
to both sides.

To isolate x, divide both sides by 7.

Answer:
Consider the following system of equations given in slope-intercept form.
y = −1
3
x + 17,
y = 5x - 23
Step-by-step explanation:
Answer:
y = (x - 4)² - 25
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
To obtain this form use the method of completing the square.
Given
y = (x + 1)(x - 9) ← expand factors using FOIL, thus
y = x² - 8x - 9
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 8x
y = x² + 2(- 4)x + 16 - 16 - 9
= (x - 4)² - 25 ← in vertex form