# Word Problem HELP!

#### jjyorg

##### New member
I guess I am a little rusty and have utilized a few friends who are just as useless for help aswering this question...
Here it is!
Write an equation that models how old in years each of you will be, when your ages add up to 150 years old. For example, if x = your age and the eldest person was a year older than you, you would write their age as x + 1. Then the equation would be: x + (x+1) = 150.

I am 28. The other individual is 33.

HELP!

#### tkhunny

##### Moderator
Staff member
Well, if you are adding up two ages to get to 150, there are a few restrictions. Most importantly, they can't BOTH be less than 150/2 = 75!!

x + (x+1) = 150 -- This seems to be consistent with everything except the very end where you gave us the ages. Quite obviously, those don't add up to 150.

#### TchrWill

##### Full Member
jjyorg said:
I guess I am a little rusty and have utilized a few friends who are just as useless for help aswering this question...
Here it is!
Write an equation that models how old in years each of you will be, when your ages add up to 150 years old. For example, if x = your age and the eldest person was a year older than you, you would write their age as x + 1. Then the equation would be: x + (x+1) = 150.

I am 28. The other individual is 33.

HELP!
If you are 28 and the other individual is 33, wouldn't the equation be x + (x + 5) = 150 or 2x + 5 = 150 or 2x = 145?

J

#### JeffM

##### Guest
jjyorg said:
I guess I am a little rusty and have utilized a few friends who are just as useless for help aswering this question...

We do not answer homework questions. We help with them. But I am taking you at your word that you are not doing homework. So let's scour some rust off.

Here it is!
Write an equation that models how old in years each of you will be, when your ages add up to 150 years old. For example, if x = your age and the eldest person was a year older than you, you would write their age as x + 1. Then the equation would be: x + (x+1) = 150.

This is a VERY good start. Just two small points. First, the question asks how old the two of you WILL be when the sum of your ages is 150. It's best to avoid possible confusion by tying your definitions of terms as closely as possible to the question posed.

SO, let x = your age at some instant in the future.

Now at this stage, we do not know the difference in ages between you and your friend. We have another variable to worry about.

SO, let y the difference in age between you and your friend.
That mean your friend's age at that future instant = (x + y).

So, the model equation is 150 = x + (x + y) = 2x + y.

One equation in two unknowns does not have a unique solution. We look for another clue.

I am 28. The other individual is 33.

Aha, y = 5.
Substitute 5 for y in the model equation.
150 = 2x + 5.
Now you do not say whether fractional years count, so you are on your own from here on.

HELP!