square garden

[solarisgirl]

The area of a square garden is A square feet and the perimeter is P feet. If A = 2P+9, what is the perimeter of the garden in feet?

a. 28
b. 36
c. 40
d. 56
e. 64

[pleasant_raj]

Let "x" be the side of square.

Area, A=x^2
Perimeter, P=4x

Given, A=2P+9
substitute value of A and P
x^2=2(4x)+9
x^2=8x+9
x^2-8x-9=0
Solving, we get (x-9) (x+1) = 0
Therefore, x=9 or x=-1
But side cannot be negative, therefore x=9

Perimeter= 4x=4*9=36

Answer B

[MAMA]

perimeter = p
side of the square = p/4
area, a = 2p +9
(p/4)(p/4) = 2p +9
solving the eq, p = -4, 36
p cannot be in -ve, so p = 36.

Bow wow wow yippee yo yippee yay!!!!11 question

Originally Posted by solarisgirl

The area of a square garden is A square feet and the perimeter is P feet. If A = 2P+9, what is the perimeter of the garden in feet?

a. 28
b. 36
c. 40
d. 56
e. 64