<h2>
Answer with explanation:</h2>
We are asked to prove by the method of mathematical induction that:

where n is a positive integer.
then we have:

Hence, the result is true for n=1.
- Let us assume that the result is true for n=k
i.e.

- Now, we have to prove the result for n=k+1
i.e.
<u>To prove:</u> 
Let us take n=k+1
Hence, we have:

( Since, the result was true for n=k )
Hence, we have:

Also, we know that:

(
Since, for n=k+1 being a positive integer we have:
)
Hence, we have finally,

Hence, the result holds true for n=k+1
Hence, we may infer that the result is true for all n belonging to positive integer.
i.e.
where n is a positive integer.
Answer:
156.86
Step-by-step explanation:
The tip of fifteen percent will be $20.46
The total will be $156.86
4d = 1/3
d = 1/3/4
d = 1/12
Thus, c is the correct choice.
The answer is isosceles.
Explanation:
Isosceles triangle is where two side lengths are equal.
Equilateral triangle is where all side lengths are equal.
Scalene Triangle is where all side lengths have different measures.
Since this triangle has two side lengths with the same measure it is an isosceles triangle.