Need help with math problem

[TheApprentice]

Here is the problem:

 

A hall is four times as long as it is wide. It has an area of 400 square meters. How long is the hall? This is as far as we've gotten: (4w)(w)=400. What's the next step?:001_huh:

 

I can figure it out using common sense, but I need help solving it using algebra. And ds hasn't gotten to square roots yet, so I don't think it should be solved that way.

 

Thanks for any help.

[regentrude]

Here is the problem:

 

A hall is four times as long as it is wide. It has an area of 400 square meters. How long is the hall? This is as far as we've gotten: (4w)(w)=400. What's the next step?:001_huh:

 

I can figure it out using common sense, but I need help solving it using algebra. And ds hasn't gotten to square roots yet, so I don't think it should be solved that way.

 

Thanks for any help.

 

 

Not sure what level you want - if he has algebra, he would know square roots of perfect squares which are prealgebra

 

4w*w=400 divide both sides by 4

w*w=100 take square root (or remember that 100 is a perfect square). No need to worry about minus signs since w must be positive.

w=10

l=4w= 40

[TheApprentice]

thanks so much. :001_smile: