0=x^2-4x+3 how many roots does this equation have

No complex roots; 3 real roots

Step-by-step explanation:

If a third order polynomial has any complex roots, then as a rule it has 1 real root and 2 complex roots. In this particular case, the polynomial has three real roots, as can be determined by graphing the function. The graph crosses the x-axis in 3 places.