Equation with fractions help?!

I'm having trouble understanding math equations such as these ones: x/3=x/4-1, and x/5-x/3=2. Any help would be appreciated.

multiply all through by the common denominator
example #1.....common denominator is 12, so....4X = 3X -12.......solve
example #2.......denom is 15...so....3X -5X = 30............solve