| m-1/3 |=0
m-1/3=0
m=1/3
原式=4m²-[6m-2(3m+2)-2m²]
=4m²-(6m-6m-4-2m²)
=4m²-6m+6m+4+2m²
=6m²+4
=6×(1/3)²+4
=6×1/9+4
=2/3+4
=14/3