Math Quadratic Equation

Question

The formula for the perimeter of a rectangle is given by P=2l+2w , where l݈ is the length and w is the width. Assume the perimeter of a rectangular plot of land is 480 ft. The length is twice the width. Find the length of the rectangular plot of land.

Is the question, I'm not sure how to figure it out

Answer 1

160 feet is the length. L= 2x, W= x, P= 480. So 2x*2 +x*2= 480, 4x + 2x= 480, 6x= 480, 6x/6= 480/6, x= 80.

L= 2x so Length = 160 feet

Answer 2

Use the equation 480=2l+2w

create the equation l=2w using the given information.

Then substitute into the first equation for l.

480= 2(2w)+2w Then multiply

480=4w+2w Then add like terms

480=6w Then divide both sides by 6

480/6=6w/6

80=w Next substitute in for the length equation

l=2w l=2(80) l=160

so the width is 80 feet and the length is 160 feet.