How do you tell if a number is divisible by three

Asmall car averages up to 29 more miles per gallon of gas that an suv. if a small car averages 44 miles per gallon, what is the average miles per gallon for an suv?

If angle 2=3x +1 and angle 3=2x +4what is angle 2

Solve the following system of equations express your answer as an ordered pair in the format (a,b) with no spaces between the numbers of symbols 5x+2y=22