Is y=-3x+2 a function? why is it/is it not a function?

It is a function.

You can try plot the graph of that equation and then plot a vertical line. You will see that the graph will only intercept the vertical line only once. That is a function.

Or you can look at the equation. Functions have the equations that start with "y=". Rather say that if you see "y" only (not y² or y³ just only y) then that is mostly a function.

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option