simplify the expression (x^4+4x^3-5x-20)÷(x+4) using synthetic division. after doing the synthetic division, which gives you just coefficients. convert the coefficient quotient answer, into a polynomial with variable x and the correct exponent powers in it. convert your coefficient answer into a polynomial.
hint: remember to fill in any missing degree terms in your dividend with coefficients that are zero to represent missing place holders.