Break even is the point of balance where you neither made a profit or loss.
We need to get how many machines will return the money he has lost. This mean how many $128 are there in $5100.
![(5100)/(128)\text{ = 39.8}](https://img.qammunity.org/2023/formulas/mathematics/college/sswngqw5ezhfslg5lmajc54jmgdvtpy16z.png)
So Henery need 39.8 machines an approximate value of 40 machines to break even.