Question

use synthetic division to find P(-3) for P(x)=x^4-2x^3-4x+4

Answer 1

Use synthetic division, where the divisor is -3. Whatever remainder you get after doing the synthetic division is P(-3). Do you know how to set up and do the synthetic division?

Answer 2

Read this is based on the remainder theorem. Read up on this and you will see why the above is true.