2x/5x-3除以3/25x平方-9*x/5x+3
=[2x/(5x-3)]÷[3/(25x^2-9)]×[x/(5x+3)]
=[2x/(5x-3)]÷[3/(5x+3)(5x-3)]×[x/(5x+3)]
=[2x/(5x-3)]×[(5x+3)(5x-3)/3]×[x/(5x+3)]
=2x^2/3