The length in feet is (x - 80) feet
The area in square feet of a rectangular field is [tex]x^2 - 140x + 4800[/tex]
The width, in feet, is x - 60
To find: length in feet
The area of rectangle is given as:
[tex]\text {area of rectangle }=\text { length } \times \text { width }[/tex]
Now we can simplify area
area = [tex]x^2 - 140x + 4800[/tex]
-140x can be rewritten as -80x - 60x
[tex]area = x^2 -80x -60x + 4800[/tex]
Taking "x" as common from first two terms and -60 as common from last two terms
area = x(x - 80) -60(x - 80)
Taking (x - 80) as common term
Area = (x - 80)(x - 60)
Substitute area = (x - 80)(x - 60) and width = (x - 60)
[tex](x-80)(x-60)=\text { length } \times(x-60)\\\\length = \frac{(x-80)(x-60)}{(x-60)}[/tex]
Cancelling (x - 60)
length = (x - 80)
Thus the length in feet is (x - 80) feet
