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"Find an question of each normal line to the curve y= x^3 - 3x that is parallel to the line 2x+18y-9=0"
As written and presented, this phrase and this combination of words IS NOT mathematically correct statement.
It does not carry or bring or conclude any mathematical or any other sense.
Not every set of word is a mathematical sentence.
As to me, it recalls me the sheet of paper with the note that was recovered from the shark's stomach in the novel
by Julie Verne "The children of captain Grant", if you read it . . .
Now, like a geographer Paganel from that novel, I can offer the way to partly decipher it:
"Find an equation of the normal line to the curve y= x^3 - 3x that is parallel to the line 2x+18y-9=0"
It is not 100% decifering yet, but at least one step to . . .