Brainliest to first correct ! asap !

Have to multiply 3 times here.  Let's begin by mult (2x^4)/(y^4) by (3x^3y)/(zy^3):

3*2 = 6

y/y^3 = 1/y^2

x^3*x*4 = x^7

z*y^3*y^4 = z*y^7

So, the product is

 3x^7*y                                                                   3x^7
and this can be reduced once more:       (answer)
  z*y^7                                                                    z*y^6