(1)移项得,x2-4x=-3,
x2-4x+4=-3+4,
(x-2)2=1,
x-2=±1,
x1=3,x2=1;
(2)移项得,2(x-3)2-x(x-3)=0,
(x-3)(2x-6-x)=0
x-3=0,或x-6=0,
解得x1=3,x2=6;
(3)a=2,b=3,c=-1,
△=b2-4ac=9-4×2×(-1)=9+8=17,
x=
=?b±
b2?4ac
2a
,?3±
17
4
x1=
,x2=?3+
17
4
;?3?
17
4
(4)x2-x-30=-24
x2-x-6=0
(x-3)(x+2)=0,
x-3=0或x+2=0,
x1=3,x2=-2.