Explanation:
t/3 + -14 = -18
first we clear up the +/- situation.
we know when + and - are combined, the result is -.
t/3 - 14 = -18
now we eliminate the free -14 constant on the left side by adding 14 to both sides (remember, we need to do changes always on both sides to keep the "=" relation: it is like with a balance).
t/3 = - 18 + 14 = -4
and now we eliminate the factor 1/3, so that t remains standing alone, by multiplying both sides by 3 :
t = -4×3 = -12
that's it. we have our answer