並前往https://www.numerade.com/ask/question/jestion-i1-write-the-following-boolean-expressions-in-sum-of-products-sop-form-flabcd-b-da-b-c-then-express-the-logical-circuit-with-nand-gates-only-yet-jowered-inaed-out-of-co-hag-question-57417/