hard number puzzle with answer

2+9=711
14+6=820
17+11=628
12+3=???

This number puzzle can be really hard. Look at the picture and numbers and try to answer it correctly. Is the number pattern obvious at first sight?

created by zbynny

Brain teaser - Number And Math Puzzle - hard number puzzle with answer - 2+9=711
14+6=820
17+11=628
12+3=???

This number puzzle can be really hard. Look at the picture and numbers and try to answer it correctly. Is the number pattern obvious at first sight?

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