Having tough time reading word probs (screen dimensions)

[joeboy]

Taking Intro and Intermediate Algebra, this is the first math I've taken in 7 years, and I am having trouble getting the equation out of word problems. Here is an example:

The dimensions of a gateway EV700 computer monitor screen are such that its length is 3 in. more than its width. If the length is increased by 1 in. while the width remains the same, the area is increased by 10 in.^2. What are the dimensions of the screen?

A=LW

Length= x + 3 is all i could get

Any help would be appreciated. Once I get the equation I do OK. Thanks

 

[mmm4444bot]

Getting Equation out of Word Problem

Hi joeboy:

I always start by making sure that I know what the question is asking for.

This question is asking for the monitor's length and width.

So, these two measurements are the "unknowns"; let's assign variables to represent them.

L = Length

W = Width

Now, we can express L in terms of W because we're told that L is 3 more than W.

L = W + 3

W = Width

You are right: Area = L * W

So, the area of the monitor is (W + 3) * W

Now, we are told that the area is 10 more if the length is increased by 1.

If the length is increased by 1, then it is:

L = W + 4

Therefore, the area of the increased monitor is (W + 4) * W

Do you understand that, if we subtract the original area from the increased area, then the result must be 10?

If this is not enough information for you to write an equation in terms of W, then please post back, and let us know what part(s) you do not understand.

I'm sure that you know once you discover W, you can easily determine L.

~ Mark

 

[joeboy]

so the equation would w(w+3) = 10 then go from there and the other monitor would be w(w+4) what?

 

[jacket81]

OKay, we know that L=3+w.
And we know that Lw+10=(L+1)w.
Now, can you solve it from there?

 

[Denis]

so the equation would w(w+3) = 10 then go from there and the other monitor would be w(w+4) what?

RELAX, joeboy :wink:

w(w+3) is the initial area;
w(w+4) is the increased area (by 10);
So:
w(w+4) - w(w+3) = 10
w^2 + 4w - w^2 - 3w = 10 : ok now?