The length of a rectangle is 4 less than twice the width. the area of the rectangle is 70 square feet. find the width, w, of the rectangle algebraically. explain why one of the solutions for w is not viable. ?

Question

30946 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-04-19T00:23:11

One answer comes out to be negative and length can never be #0# or below.

Let #w = "width"#

Let #2w - 4 = "length"#

#"Area" = ("length")("width")#

#(2w - 4)(w) = 70#

#2w^2 - 4w = 70#

#w^2 - 2w = 35#

#w^2 - 2w - 35 = 0#

#(w-7)(w+5) = 0#

So

#w = 7# or #w = -5#

#w = -5# isn't viable because measurements have to be above zero.