Question 845343
This is a simple quadratic equation. To solve this you simply use the quadratic formula

*[invoke quadratic "x", 2, 3, 19 ]


The roots are complex because the discriminant is negative. Anytime you have a negative square root, you have an imaginary number. A complex number is a real number plus an imaginary number of the form

a+-bi where a and b are real and i is the imaginary unit sqrt(-1). 

In this case the roots are -3+11.95i/4 and -3-11.95i/4.