Answer: a. 8.4 meters b. 14 wreaths
Explanation:
The following equation shows the problem, with x representing the number of wreaths made:
12 = 9(0.4) + 0.6x
To answer a, get 0.6x alone:
12 = 9(0.4) + 0.6x
12 = 3.6 + 0.6x
8.4 = 0.6x
There were 8.4 meters available to make wreaths
To answer b, get x alone
8.4 = 0.6x
14 = x
Diego could make 14 wreaths with the available ribbon
Hope this helps!