If x represents a number, then write an expression for a number that is three more than one third the value of x.

How do i do this? i don’t understand

Measures of the angle of r, 31 s (x+4) t (3x+9)

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?