What is 10 rounded to the nerest 10

What signals you that factoring by grouping is the best method to use when factoring a problem?

Anyone know? is appreciated! will mark brainliest if correct!

Answer asap! show all work! find the number of complex roots, the possible number of real roots and the possible rational roots of the polynomial function. then, solve for all roots. x^3 + 2x^2 + 3x + 6 = 0