Answer:
a) 
b) 
c) 
Step-by-step explanation:
a) Geometric sequence with first term 5 and common ratio 2, where the nth term can be calculated via:

The first five terms are: 
b) Geometric sequence with first term 100 and common ratio 1/2, where the nth term can be calculated via:

The first five terms are: 
c) Geometric sequence with first term 160 and common ratio -1/2, where the nth term can be calculated via:

The first five terms are: 
Answer:
x=35
Step-by-step explanation:
3x+3=108
3x=108-3
3x= 105
x= 105/3
x=35
Answer:
If P= price of the hardcover book, then
We have to spend $25-P, if P<$25; or $0 if P>= $25
Step-by-step explanation:
Lets call P the price of the hardcover book, in $. We can suppose that P is less than 25, otherwise we shoudnt spend on anything else to get the free shipping. If X is the amount that we have to spend to reach 25, then we get that P+X = 25. If P is known, we can obtain X by substracting P in both sides, therefore
X = 25-P
We conclude that if the price of the book P is less than 25, then we have to spend $25-P. Otherwise we have to spend 0.
Answer:
11 years old
Step-by-step explanation:
If four brothers have the average age 6, then the sum of their ages is

years.
Let x years be the age of sister. If four brothers and their sister have the average age 7, then

Multiply this equation by 5:

The sister is 11 years old.
Answer:
You will multiply the scale factor by the vector