MathDB

Find all the roots

r_{1}

r_{2}

r_{3}

r_{4}

of the equation 4x^{4}\minus{}ax^{3}\plus{}bx^{2}\minus{}cx\plus{}5 \equal{} 0, knowing that they are real, positive and that: \frac{r_{1}}{2}\plus{}\frac{r_{2}}{4}\plus{}\frac{r_{3}}{5}\plus{}\frac{r_{4}}{8}\equal{} 1.

Problem Statement