Have two pre-test problems that I am confused on how to do

These are I know supposed to be solved using the Principle of Zero Products -- but I did not understand what the instructor said and when I stayed after class to ask for help, I didn't get it.

problem is 3x^2 - 4x = 0 and the way this test works is I have to pick an answer -- but I am not even sure how to factor it...
The only example I have is
x^2 - 5x = 0
x(x-5) = 0
x = 0 or x - 5 = 0

but how do I factor -- does this look ok? -- opps left off the x on the 4 -- hope this now makes sense
3x^2 - 4x
x(3x - 4) = 0
x = 0 or x = 4/3

Hi swampy. The factoring looks fine to me.

Maybe the reason you didn't understand it is that one of the basic principles slipped your mind.

When the product of two things is zero, one of those two factors (or both of them) MUST be zero. That's because anything multiplied by 0 equals 0.

So, to figure out what x is in x (3x - 4) = 0, either x = 0, or 3x - 4 = 0, or both, because those are the two factors that, when multiplied together, give you 0.

Do you see what I mean?