By definition, the area is given by:
[tex] A = w * l
[/tex]
Where,
w: width
l: length
We have two expressions for the length:
[tex] L = 14
L = 5 + 3c [/tex]
Since the length is the same, we equate both expressions:
[tex] 5 + 3c = 14
[/tex]
From here, we clear the value of c:
[tex] 3c = 14 - 5
3c = 9
[/tex]
[tex] c = \frac{9}{3}
c = 3
[/tex]
Then, we have that the width is given by:
[tex] W = 6c-8
[/tex]
Substituting the value of c we have:
[tex] W = 6 (3) -8
W = 18-8
W = 10
[/tex]
Finally, the area is given by:
[tex] A = w * l
A = 10 * 14
A = 140 ft ^ 2
[/tex]
Answer:
he should order 140 square feet
