Four roads (1) (2X^2-X+1)/(2X+1)>0 (2) 1/2X^2-1/3X+1/5≥0 (3) (X-1)/(X-2)>1/2 (4) (X-4)/(X^2+X-2)>0

Four roads (1) (2X^2-X+1)/(2X+1)>0 (2) 1/2X^2-1/3X+1/5≥0 (3) (X-1)/(X-2)>1/2 (4) (X-4)/(X^2+X-2)>0

(1) The formula can get (2x2-x + 1) = 2 (x-1 / 4) 2 + 7 / 8 > 0, so only 2x + 1 > 0, the answer is x > - 1 / 2 (2) 1 / 2x2-1 / 3x + 1 / 5 ≥ 0, both sides multiply by 2, can get x2-2 / 3x + 2 / 5 ≥ 0, formula can get (x-1 / 3) 2 + 2 / 5-1 / 9 > 0, constant set up (3) simplify x2-3x + 3 / 2 = (x-3 / 2) 2-3 / 4 > 0