解
2x²-3x-7
=2(x-m)²+n
=2(x²-2mx+m²)+n
=2x²-4mx+2m²+n
∴4m=3,2m²+n=-7
∴m=3/4
∴2×(9/16)+n=-7
∴n=-7-9/8=-65/8