並前往https://books.google.com.tw/books?id=KcsWAAAAQBAJ&pg=PA86&lpg=PA86&dq=Factor+and+simplify+to+obtain+a+product-of-sums+expression+with+four+terms:+abc+d+e+ace+b+C+D&source=bl&ots=ZsneVE22XI&sig=ACfU3U0kYIsUp_0QXw4tRDvqhZnazp_pFw&hl=zh-TW&sa=X&ved=2ahUKEwiz9LvQyPT4AhWqklYBHe5iA5oQ6AF6BQiMARAD