30 points! which relations represent functions? multiple answers

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

What is the point-slope equation of a line with slope -5 that contains the point (6,3)

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?