Perimeter of a rectangle-is this?

Question

The width of a rectangular playground is 2x – 5 feet, and the length is 3x + 9 feet. Write a polynomial P(x) that represents the perimeter and then evaluate this perimeter polynomial if x is 4 feet.

Answer 1

Perimeter is simply the sum of the lengths of the sides. There are 4 sides: 2 "lengths" and 2 "widths"
P = 2L + 2W
P = 2(3x+9) + 2(2x-5)
Simplify this (by using the distributive property and combining like terms).
Then plug in 4 for x.

Answer 2

first..add all the sides together....(2x-5)+(2x-5)+(3x+9)+(3x+9)..this comes to 10x+8. this is the polynomial that represents the perimeter. then substitute x for 4...we get 10(4)+8 which comes to 40+8.....total of 48.
have fun

Answer 3

Perimeter is 2(a+b)

so the P(x) = 2([2x-5] + [3x+9]) ft

Answer 4

P(x) = 2W + 2L = 2(2x-5)+2(3x+9)
= 10x + 8.

If x=4, then P(x) = P(4) = 48.

Answer 5

it would be a square because 2x4=8-5=3. and 3x4=12-9=3. the perimeter woul be 12.

Answer 6

since you know the terms for the width and length and the value of x...go ahead and solve each term by substitution.

(2x4)-5 and (3x4)+9

simplify...which gives you

8-5=3 for width (w) and 12+9=21 for the length (l)

since equation for perimeter (p) is

p=2w+2l,

just substitute and solve

Answer 7

2(2x -5) + 2(3x+9) = 4x -10 + 6x + 18 = 10x + 8
if x =4, 10.4 +8 = 48 feet

but if you don't learn how to find that out by yourself, that will do no good.

Answer 8

2(2x-5)+2(3x+9)

2(8-5)+2(12+9)

2(3)+2(21)

6+42

48 feet

Answer 9

49 feet

Answer 10

You get some amazing wrong answers, eh?

As for example 12. I like that one especially.