I loved this puzzle. It took a lot of work, but I think I figured out some logical steps.
Spoiler
The strip with a four at the top can’t be flipped and has to be the first or last strip.
It doesn’t take too much checking to realize it can’t go first, so it must go last.
Figuring out how to have one equals sign per row is important too.
From there, it was a lot of guess and check.
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