Jon P. answered 01/22/15
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Let x be the number of books produced.
With method A, the total costs would be the fixed cost of 68694 plus 10.25 per book, or 10.25x. In other words 68694 + 10.25x
By the same reasoning, the total costs With method B would be 22305 + 22x.
So set these two expressions equal to each other. Whatever x comes out to be in that equation will be the number of books resulting in equal costs between the two methods.
So 68694 + 10.25x = 22305 + 22x
Subtract 22305 from both sides:
46389 + 10.25x = 22x
Subtract 10.25x from both sides:
46389 = 11.75x
Divide both sides by 11.75:
3948 = x
So the answer is 3948 books.
Plug this back for x in either cost equation to get the total cost:
22305 + 22 * 3948 = 109161
To check the result, plug the value for x into the other equation to make sure it is the same:
68694 + 10.25 * 3948 = 109161