The back of plywood is damaged after cut or drill. How to prevent it?
put a piece of 2x4 under the board when you drill it.

the drill bit has to drill into the 2x4

clamp the board down against the 2x4 if you can

https://www.woodmagazine.com/woodworking-tips/techniques/sawing-solutions/pointers-for-perfect-plywood-cuts

use a fine toothed blade to cut the board

raise blade as high as possible

place board good-side-up

use masking tape ... cover cut line so that the blade cuts the tape in 1/2 lengthwise 

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_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  &lt; cut along dotted line
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