Answer: 17.14 ft
<u>Step-by-step explanation:</u>
The area of the flower bed is 60 ft x 80 ft = 4800 ft²
The perimeter of the sidewalk that surrounds the flower bed is:
- 2(60 ft) + 2(80 ft)
- = 120 ft + 160 ft
- = 280 ft
The area of the sidewalk is:
area of sidewalk = area of flower bed
280w = 4800


≈ 17.14
Step-by-step explanation:
We have got the lines :

Both lines intercept the x-axis in the point :

In all point from x-axis the y-component is equal to 0.

We replace the I point in the lines equations:

From the first equation :

From the second equation :

Then 
Finally :

y = ax + b and y = cx + d have the same x-intercept ⇔ad=bc
For this question , you just need to divide 1 7/8 with 1/12
1 7/8 : 1/12
= 15/8 : 1/12
= 15/8 x 12/1
= 22.5 bags.
So i guess she can make around 22 full bags
hope this helps