## Answer

## Step by step solution

Problem

To find the roots of a polynomial of the form $ax^2+bx+c$ we use the quadratic formula, where $a=1$, $b=3$ and $c=10$

Substituting the values of the coefficients of the equation in the quadratic formula

Multiply $-1$ times $3$

Calculate the power

Add the values $9$ and $-40$

Calculate the power using complex numbers

To obtain the two solutions, divide the equation in two equations, one when $\pm$ is positive ($+$), and another when $\pm$ is negative ($-$)

Simplifying

Applying the quadratic formula we obtained the two solutions $x_1$ and $x_2$, with which we write the solution interval