If pm * p8= p16, and (p9)n =p-27, what is the value of m-n?

The first rule you have to know is

In other words, if you multiply two powers of the same base, you have to sum the exponents. So, we have

Which equals if and only if and thus .

The second rule you have to know is

In other words, to evaluate the power of a power, you have to multiply the exponents. So, we have

Which equals if and only if and thus .

Now that we found and , it's easy to conclude that

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