Question 998816

Why use synthetic division?
Why not just substitute {{{-1}}} for {{{y}}} in the equation?

{{{f(y)=13y^4+5y^3–12y^2–18y–32}}}

{{{f(-1)=13(-1)^4+5(-1)^3–12(-1)^2–18(-1)–32}}}

{{{f(-1)=13(1)+5(-1)–12(1)–18(-1)–32}}}

{{{f(-1)=13-5–12+18–32}}}

{{{f(-1)=31-49}}}

{{{f(-1)=-18}}}