∵方程有两实根
∴△≥0
∴△=k²-4x(3k²/4-3k+9/2)≥0
=k²-3k²+12k-18≥0
=-2k²+12k-18≥0
=k²-6k+9≤0
=（k-3）²≤0
∵△≥0
∴k=3