Answer:
0.74 feet should be added to each side of the grassy space.
Step-by-step explanation:
Let
x -----> the width of the walking track around the space
we know that
The total area is equal to
[tex]A=(6+2x)(8+2x)[/tex]
[tex]A=71\ ft^{2}[/tex]
so
[tex](6+2x)(8+2x)=71\\48+12x+16x+4x^{2}=71\\4x^{2}+28x+48-71=0\\4x^{2}+28x-23=0[/tex]
Solve the quadratic equation by graphing
The solution is x=0.743 ft
see the attached figure
therefore
0.74 feet should be added to each side of the grassy space.