Question

3a-2b+c=0 12a+4b+c=0 -a+b-c+d=0 8a+4d+2c+d=0求a.b.c.d的值,

Answer 1

3a-2b+c=0 -----------(1)

12a+4b+c=0 ----------(2)

-a+b-c+d=0 ----------(3)

8a+4b+2c+d=0---------(4)

(4)-(3)式得

9a+3b+3c=0

3a=-b-c

由（1）得

3a=2b-c

b=0

3a=-c,12a=-c

a=0,c=0

d=0

a=b=c=d=0