To combine two fractions into one fraction if they are being added / subtracted from each other, make it so they share the same denominator. To do this, one way is to make [tex]\frac{1}{3}[/tex] have denominator [tex]3t[/tex], so multiply the top and bottom of the fraction by [tex]t[/tex]:
[tex]\frac{t+2}{3t} - \frac{t}{3t}[/tex]
and now you can just subtract the numerator.
[tex]= \frac{t+2 - t}{3t} = \frac{2}{3t}[/tex]