(1)方程移项得:x 2-4x=8,
配方得:x 2-4x+4=12,即(x-2) 2=12,
开方得:x-2=±2
3 ,
则x 1=2+2
3 ,x 2=2-2
3 ;
(2)原式=(
3 ) 2+4×
1
2 ×
2
2 =3+
2 .