Step  1  :
             d
 Simplify   ——
            dy
Canceling Out :
 1.1    Canceling out d  as it appears on both sides of the fraction line
Equation at the end of step  1  :
  1
  — • y3x3
  y
Step  2  :
Dividing exponential expressions :
 2.1    y3 divided by  y1 = y(3 - 1) = y2
Final result :
  y2x3