
In other words, how many ways are there to choose

objects from a total of

objects? Just one; take all of them at the same time.
the answer would be the third choice which is N(0, z)
8x-4 and 4(2x-1)
4(2x-1) the four needs to be distributed in the parentheses.
4*2x=8x
4*(-1)=(-4)
8x-4=8x-4