Can someone double checck my work on perimeter?

Question

A construction company builds a swimming pool with a perimeter of 56 m. The length is 12 m more than the width. Find the dimensions of the swimming pool?

I choose D as the answer...am i right?

A. 20 m × 8 m

B. 20 m × 12 m

C. 15 m × 8 m

D. 25 m × 8 m

Answer 1

let the length be x and the width be x - 12...

2(x + x - 12) = 56

2x - 12 = 28

2x = 40

x = 20

therefore...

the length is 20m...AND...the width is 8m

therefore...

the dimensions is...

20m x 8m

AND...

u are wrong...

Answer 2

no, the answer is a

Answer 3

it is A  

Answer 4

P = 56m

L = W + 12

P = 2L + 2W

56 = 2*(W + 12) + 2W

2W + 24 + 2W = 56

4W = 56 - 24 = 32

W = 32/4 = 8

So, L = 8+12 = 20

Dimension = L*W = 20*8m

Answer is A.

Answer 5

Its A.

2(x)+2(x+12)=56

4x+24=56

4x=32

x=8

Width =8 Length= 20

Answer 6

  Let width of pool be = x ,

  therefor length of pool = 12 + x

  2 x + 2 ( x + 12)        = 56

  2 x + 2x + 24            = 56

  4 x                           = 56 - 24 = 32

  x                              = 32 / 4   = 8

  width of pool              = 8 metres

  and length of pool      = 20 metres