a rectangular region has area of 91 sq. ft. The length of the region is one less than twice the length. find the dimensions.

Question

jpes2193 · Answer

Why is my teacher using the quadratic formula to solve this??? I've not see its done this way before. The answer is L=13  W=7. Im highly confused about the use of the quadratic formula.

jpes2193 · Answer

@dtan5457

amorfide · Answer

you know the length is one less than twice the length

so you can make an expression for length and width
let's say width=x
then you know length is twice this, then minus one

width=x
length=2x-1

Area of a rectangle is LW
A=LW

multiply them, then you know Area is 91

make LW=91

then solve for x