4x^2y - 8xy?

1. 4x^2y - 8xy
=[4x^2y - 8xy]/4xy
=x-2
or
-1[-x=-2]
x=2


2. (2x + 4)(3x - 1)
=6x^2 - 2x + 12x -4
=6x^2+10x-4
=[6x^2+10x-4]/2
=3x^2+5x-2

1)
4x^2y - 8xy
= 4(x^2y - 2xy)
= 4xy(x - 2)

2)
(2x + 4)(3x - 1)
= 2x*3x + 4*3x - 2x*1 - 4*1
= 6x^2 + 12x - 2x - 4
= 6x^2 + 10x - 4

What now ?
4xy (x - 2) ?

OK this might take a bit. * = Multiply
(2x * 3x) + (2x * -1) + (4*3x) + (4*-1) Disregard brackets (tell you what they mean at bottom)
this is
6x^2 + -2x + 12x + -4
that =
6x^2 + 10x - 4

OK, the thing to do is multiply the first equation's first number by both the second equations numbers. Shown in the first 2 brackets
Then multiply the second number in the first equation by the 2 numbers in the second equation. Sown in the last 2 brackets

4x^2y - 8xy=
4xy(x-2)

(2x + 4)(3x - 1)=
6x^2+12x-2x-4=
6x^2+10x-4

If you meant that 4x^2y - 8xy is equal to (2x+4)(3x-1),
then 4x^2y - 8xy=(2x+4)(3x-1)
4xy(x-2)=6x^2+10x-4
y=(6x^2+10x-4)/[4x(x-2)]
or
y=(3x^2+5x-2)/[2x(x-2)]

okay...
(2x+4) (3x-1)
First, 2x*3x = 6x^2
Then 2x*-1= - 2x
Then 4*3x= 12x
Finally, 4*-1= - 4
So then u get:
6x^2-2x+12x-4
which is equal to:
6x^2+10x-4

Hope this helps!