Answer:
68.42
Explanation:
We know that when we add the lengths of all of the desks together, the total is 214.62. Based on that information, we can set up the following equation: 67.94 + 78.26 + x = 214.62. From there, all you have to do is add 67.94 + 78.26 to get 146.2. Lastly, you simply do 214.62 - 146.2 to get 68.42. Hope this helps!