PDA

View Full Version : inequalities: the width of a rectangle is 6 cm more than....



jehan.the.great
05-30-2006, 07:57 PM
"the width of a rectangle is 6 cm. more than one half the length and the perimeter is at most 72 cm. Find the maximum dimentions of the rectangle. (let x = the length of the rectangle)"

so far i got
2x + 2(1/2 + 6)<72
x20

but im clueless about the rest.

stapel
05-30-2006, 08:02 PM
If "x" is the length, then the only way "6 + 1/2" could be the width is if x = 1. Is this given somewhere in the exercise?

Also, what does "x20" mean?

Thank you.

Eliz.

jehan.the.great
05-30-2006, 08:26 PM
ooo sorry i meant

x<20

skeeter
05-31-2006, 10:15 AM
the width of a rectangle is 6 cm. more than one half the length and the perimeter is at most 72 cm. Find the maximum dimentions of the rectangle. (let x = the length of the rectangle)

you are correct, the rectangle's length has to be less than or equal to 20

w = 6 + (x/2)

2w = 12 + x

2w - 12 = x

since x < 20, 2w - 12 < 20

find the range of values for the width, w.