Area = length x width = (w) x (w+4) We are told the the length is 4 ft longer than the width
So (w)(w+4)=21
w^2 +4w-21=0
(w+7)w-3)=21. Two solutions w=-7. W=3. We can discard w=-7 since we cannot have a negative distance as the answer for a side
So width= 3 length=7
If we add a 1.5 ft border both dimensions increase by 1.5 to 4.5 and 8.5
New area (4.5)(8.5)= 38.25
Stephen K.
09/08/20
Lilly P.
w^2 +4w-21=0 how did you get from here (w+7)w-3)=21 to here? Can you explain the steps?09/08/20