The perimeter of a rectangle is 30 inches. if it's length is three times it's width, find the dimensions. show work if possible.
next, a volleyball coach plans her daily practices to include 10 minutes of stretching, 2/3 of the entire practice scrimmaging, and the remaining practice time working on drills. on wednesday, the coach planned 100 minutes of stratching and scrimmaging. how long, in hours, is the entire practice? show work if possible.
homework due !

The rectangle problem:

First, create some variables.
w = width
l = length

Then you know that the length is 3 times the width, so
l = 3w

The equation for perimeter is
P = 2(l+w)

Now you use substitution, substituting the 3w for l because you found that earlier.

P = 2((3w) + w)

And simplify.
P = 2(4w)
P = 8w

And you know P = 30 because they told you that.
30 = 8w
w = 15/4 inches, or 3.75 inches

Now substitute that value back into that first equation,
l = 3w
l = 3(15/4)
l = 45/4 inches, or 11.25 inches.

The dimensions are 11.25in for length and 3.75in for width.



The volleyball problem:

100 minutes of stretching and scrimmaging combined, and you know 10 have to be stretching, so 90 is scrimmaging.

s = scrimmaging
T = total time

s = 2/3T   (they gave you this)
90 = 2/3T
T = (90*3)/2
T = 270/2
T = 135 minutes, or 2 hours and 15 minutes.

X> -2 is the simplified version.