Plz factor
2x^2+17x-21

2x^2 + 17x -21 cannot be factored nicely, if it was +21 you could, but the zeros for this have to gotten using the quadratic equation

-b +/- (b^2-4ac)^1/2
     2a
so

-17 +/- (17^2-4(2)(-21))^1/2
       2(2)
-17 +/- (457)^1/2
       4

so the zeros are roughly 1.094 and -9.594