Hi... something's not copied correctly in your problem.
sin 100 = 0.9848
5/9 of that is 0.5471
that happens to also be sin 33.17
So maybe it was ... sin A = (5/9)(sin 100)
or sin A = (5 sin 100)/9
or 9 sin A = 5 sin 100
But that's the only thing that makes sense, that you are suppose to be showing the sine of 33.17 degrees is equal to the same thing as (5 sin 100) /9.
Hope that helps.