Solve: log2(x2 - 5x + 7) >= 0
---> x2 - 5x + 7 >= 20
---> x2 - 5x + 7 >= 1
---> x2 - 5x + 6 >= 0
---> (x - 3)(x - 2) >= 0
Areas tp check: (-infinity, 2) (2) (2, 3) (3) (3, ininity)
Checking values from each area indicate that the values below 2, 2, 3, and above 3 work.
Only those values between 2 and 3 do not work.
---> answer: (-infinity, 2] union [3, infinity)