The ratio #30/45# is not in simplest terms (meaning the numerator and denominator have nothing in common), so to find a ratio equivalent, you must reduce the fraction.
So first, you must think to yourself, what do #30# and #45# have in common? Since they both have #5# in common, you would need to divide #30# by #5#, and #45# by #5#.
#(30-:5)/(45-:5)#
You are left with the fraction or ration #6/9#, which is equivalent to #30/45#. However, this can be reduced even more, since #6# and #9# both are divisible by #3#.
#(6-:3)/(9-:3)#
Now, your final answer is #2/3#
