[(2/3x)+y]/[2x-(5/2y)] 分子分母同乘以3x.
=(2+3xy)/[6x^2-(15x/2y)] 再分子分母同乘以2y.
=(4y+6xy^2)/(12x^2y-15x)
等于(12x^2y-15x)分之(4y+6xy^2)