(1)∵2x 2+x-3=0,
∴(2x+3)(x-1)=0,
∴x 1=-
3
2 ,x 2=1,
∴x 1+x 2=-
1
2 ,x 1x 2=-
3
2 ;
故填空答案: -
3
2 ,1, -
1
2 ,-
3
2 .
(2)x 1+x 2=-
b
a ,x 1x 2=
c
a ;
故填空答案: -
b
a ,
c
a .
(3)根据(2)可知:
x 1+x 2=-1,x 1x 2=-3,
则x 1 2+x 2 2=(x 1+x 2) 2-2x 1x 2
=(-1) 2-2×(-3)
=7.