Question

the length of a rectangle is 9 more than the width. the area is 220 square feet. find the length and the width of the rectangle.

Answer 1

A=LW and L=W+9  so

A=(W+9)W

A=W^2+9W

W^2+9W-A=0, since A=220

w^2+9w-220=0

w^2+20w-11w-220=0

w(w+20)-11(w+20)=0

(w-11)(w+20)=0

Since w>0

W=11 ft, and since L=W+9

L=20 ft

Answer 2

In a problem like this best thing you can do is draw a picture of a rectangle the width would be w because we don't know the width , the length would be 9 + w because it is 9 more than the width , on the inside of the rectangle you would write 220 since the area is 220 , area = lw right so plug in what you know , you know area , and length . Your equation is now 220=(9+w)(w) what I do is either guess and check or distribute out the w and from there you can guess and check or keep solving the equation