Question

The sum of x and 9 is divide by 2. That quantity is equal to 3x

Answer 1

your equation would be set as 3x=(9+x)\2 hence you proceed by putting the like terms together so x is basicly moved to the other side of the equals sign hence the equation reads 3x -x=9\2....after working out,you get that the result so far is 2x=4.5.....so now simplify to find value of x,so x=2.25

Answer 2

(x+9)/2=3x would be your equation set up
cross multiply to get x+9=6x
simplify to get 9=5x
divide both sides by 5 to get x alone and get 9/5 as your answer
or 1 and 4/5 or 1.8