Senior high school students are generally unary quadratic inequalities, and the solution is as follows: when △ = b 2-4ac ≥ 0, the quadratic trinomial, ax 2+bx+c has two real roots, then ax 2+bx+c can always be decomposed into the form of a(x-x 1)(x-x2). In this way, solving a quadratic inequality can be reduced to solving two linear inequalities. The solution set of unary quadratic inequality is the union of the solution sets of these two unary linear inequalities. Example: Try to solve the unary quadratic inequality 2x 2-7x+6 0 (x-2), the index is 2, which is even, so when drawing a curve on the number axis, it does not pass through point 2, while the index of (x-3) is 1, which is odd, so when drawing a curve on the number axis, it passes through point 3.