Question 1133474
What if you were to test the "root" as being {{{-17}}}?  The value for your cubic polynomial at x=-17 will be what you are looking for.



Also, with synthetic division:
<pre>
-17   |   1   -1   -226    1410
      |
      |      -17   306     -1360    
      |___________________________
          1  -18   80      50
</pre>
Remainder is 50.