Solve using foiling. Ignore the -1 to begin with and just look at the part in parenthesis. Do x from the first parenthesis times the stuff in the second parenthesis.
ie: x(x) and x(6)
ie: x^2 + 6x
Then do the 5 times the things in the second parenthesis.
ie: 5(x) and 5(6)
ie: 5x + 30
Then add what you got from multiplying the first value to what you got from multiplying the second.
ie: x^2 + 11x + 30
This is a trinomial because it has three different variables. Now change all the signs to negative because of the -1 out front.