Answer:
2 m
Step-by-step explanation:
First we need to calculate the actual area of the garden:
Area = 16 * 8 = 128 m2
If the new area is 240 m2 and we call the width of the pathway 'w', we have that:
New area = (16+2w) * (8+2w) = 240
128 + 48w + 4w^2 = 240
4w^2 + 48w - 112 = 0
w^2 + 12w - 28 = 0
Delta = 12^2 + 4*28 = 256
sqrt(Delta) = 16
w1 = (-12-16)/2 = -14 m (not a valid width)
w2 = (-12+16)/2 = 2 m
