The three zeroes of the polynomial 2x3 + 5x2 - 28x - 15 _____
Are all rational numbers
One zero of this polynomial , by the method of Hit and Trial is 3 .Now, by long division of 2x3 + 5x2 - 28x - 15 by (x -3 ) , we have 2x2 + 11x + 5 factors of which are ( 2x + 1 ) and (x + 5 ).
Therefore, the three zeros of the polynomial 2x3 + 5x2 - 28x - 15 are all rational numbers