First thing to do when we look at that equation is try to find a number that is greater than 1 and that we can factor both 6 and 9 with, and after thinking we find out that we have 3 as a factor for this equation that we can factor 6 to be 2 by dividing it by 3 and 9 to be 3 also by dividing it by 3 and replace them in the equation:

6t+9= (3*2t)+(3*3)= __3(2t+3)__