Translate the following phrase to a mathematical expression. the product of a number and nine a  n + 9b n - 9c 9 nd n/9

The correct answer is:   [c]:   " 9 n " .  note:   this answer choice:   [c]:   " 9 n " ; is correct; since: "the product of a number and nine" ;   →   refers to "a number", multiplied by "9" ;   → which is the same as:   "9", multiplied by "a number" ;   → and   "answer choice:   [c]:   " 9 n " ;               is the only possible correct answer choice; in which "n" represents an "unknown number".let us consider the other answer choices:   choice:   [a]:   " n + 9  " ; is incorrect;   since this choice represents:                         →   "the sum of "9" and "a number" .  choice:   [b]:   " n  − 9" ; is incorrect; since this choice represents:                         →   "the difference between   "a number"   and "9" .  choice:   [d]:   " n/9 " ; is incorrect; since this choice represents:                         → "a number", divided by "9" ;                             that   is:   "the quotient of "a number" and "9" .

The answer is 41.7 because 1.39 times 30 is 41.7