Thread: word problem and interval notation

I never liked wp's

the perimeter of a standard rug is 44ft the length is 2ft longer than the width find the dimensions width and length anyone please?


interval notation of the set {xl -2 > x > 6}

is it (-6 -2) ?

Originally Posted by rj2001

I never liked wp's

the perimeter of a standard rug is 44ft the length is 2ft longer than the width find the dimensions width and length anyone please?


interval notation of the set {xl -2 > x > 6}

is it (-6 -2) ?

Are you sure this is the right question? to have an interval for such a question, we need an inequality. there's no inequality here.

let width = x
=> length = x + 2
=> Perimeter = 2x + 2(x + 2) = 44
=> 2x + 2x + 4 = 44
=> 4x + 4 = 44
=> 4x = 40
=> x = 10

so the width is 10 and the length is 12

so the rug is a 10 x 12 rug

EDIT: oh, the interval thing is for the second question, ok i'll do that...what is xl?

ok, so {x| -2> x > 6} makes no sense. what you are actually saying is x is less than -2 but greater than 6. I think it should be {x| -2 < x < 6}, that is, x is greater than -2 but less than 6.

so in interval notation that would be (-2,6). we use parenthesis as oppsosed to square brackets since x cannot be equal to either of the values at the end points.

Hello, rj2001!

Is that interval problem stated correctly?
If it is, it's not the way we should write it.

interval notation of the set {x l -2 > x > 6}

It says: x > 6 . (x is greater than 6)
. . and: -2 > x . (x is less than -2)

This is clearly impossible; a number cannot be greater than 6 and less than -2.


The intent could have been: .x < -2 .or .x > 6

And the interval would be: .(-∞, -2) U (6, ∞)

hi yeah sorry for not making it clear that was 2 problems in one post

but yeah the second one is on our online homework (mymathlab) multiple choice

Write interval notation for the set

{ x l -2 > x >-6 } the l = absolute value bar? but just one no close

answers are
(-6,-2)
[-6,-2]
[-6,-2)
(-6,-2]

this is a review from a chapter wayy back and I think he read it x is such that? something dunno if that will help

x is between -2 and -6, but neither of the two numbers is included.
Which means that x is not equal to either -2 or -6, but lies between them.

For the rug:
Perimeter = 2L + 2B
But L = (x + 2)
B = (x)

44 = 2(x + 2) + 2(x)
44 = 4x + 4
x = 10

Thus B = 10
And L = 10 + 2 = 12