If we add the coefficients and the constant term and get 0, then 1 is a root
So....this is true
Using synthetic division, we can reduce the polynomial......
1 [ 1 3 3 - 3 - 4 ]
1 4 7 4
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1 4 7 4 0
So......the remaining polynomial is
x^3 + 4x^2 + 7x + 4
Note that if we sub - 1 into this, we get 0
So......the rational roots are 1 and -1