Question 93090
30*40=1200 area of the garden.
1800=(30+2w)(40+2w) these are the dimentions of the garden plus the walk way.
1800=1200+80x+60w+4w^2
4w62+140w+1200-1800=0
4w^2+140w-600=0
4(w^2+35w-150)=0
using the quadratic equaton we get:
{{{w=(-b+-sqrt( b^2-4*a*c ))/(2*a)}}}
w=(-35+-sqrt[35^2-4*1*-150])/2*1
w=-35+-sqrt[1225+600])/2
w=(-35+-sqrt1825)/2
w=(-35+-42.72)/2
w=(-35+42.72)/2
w=7.72/2
w=3.86 ft. is the width of the walkway