anonymous 5 years ago List all possible rational solutions. y=5x^(3)-2x^(2)+3x-8 Show work. Thanks?

1. anonymous

make a fraction. numerator must divide 8 so you have several possibilities : 1,2,4,8 denominator must divide 5 so only 2: 1,5 and of course they could be positive or negative. so you get a bunch of fractions that look like so you get $\pm 1$ $\pm2$ $\pm4$ $\pm 8$ those are the ones divided by 1 and you also get $\pm \frac{1}{5}$ $\pm \frac{2}{5}$ $\pm\frac{4}{5}$ $\pm \frac{8}{5}$

2. anonymous

btw i hope it is clear that the are POSSIBLE RATIONAL zeros. a cubic polynomial can have at most 3 zeros. and they need not all be rational.