Expressions and Equation

[Lasky]

Hello everyone, I really need help finding the algebraic expression for this problem so I can solve for x. Please help.

1. Assume that every week after the week you counted your number
of contacts you add another person to the list.

a. Write an equation that will tell you how many people will be on
your list in x number of weeks.

b. Figure out how many people will be on your list in 12 weeks.

c. Figure out how many weeks it will take to have 200 people on
your list.

 

[Lasky]

This is a problem I am trying to solve for my math homework in school. I've been trying to come up with an equation and I am having problems finding the correct one. After the first week I have 30 contacts, after that, I am lost. Please!!

 

[mmm4444bot]

After the first week I have 30 contacts

Ah -- this is the crucial piece of information missing from your original post. (If we don't know what the starting number is, we can't know what any ending number might be.)

I'm not sure what you've been shown in class, but the scenario in this word problem leads to what we call an arithmetic sequence. (An arithmetic sequence is simply a list of numbers where all adjacent entries differ by a fixed amount.)

The number of contacts in this exercise differ by 1, from week to week.

Week1: 30 contacts
Week2: 31 contacts
Week3: 32 contacts
Week4: 33 contacts
Week5: 34 contacts

et cetera

The exercise instructs you to use the symbol x for representing the week numbers.

We may pick the symbol y to represent the contact numbers.

So, we are looking for an equation of the form:

y = some expression that contains symbol x

Hence, we may now think about the list this way:

x = 1; y = 30
x = 2; y = 31
x = 3; y = 32
x = 4; y = 33
x = 5; y = 34

et cetera

Do you see a pattern between x and y values, above?

If not, try thinking this way:

x = 1; y = 30 + 0
x = 2; y = 30 + 1
x = 3; y = 30 + 2
x = 4; y = 30 + 3
x = 5; y = 30 + 4

Please let us know what you think or try next. Cheers :cool:

 

[mmm4444bot]

You are told to use x as the number of weeks after your initial count of 30.

I'm reading it a bit differently. I think that x is the week number, including the first week.

What happens after week one is that the number of contacts grows.

One could set-up a formula under either interpretation, of course, as long as the values end up correct.

Cheers :cool: