由题目可知:a = (b/a)^4 , c= (d/c)^2∴a-c=[(b/a)^2+(d/c)][(b/a)^2-(d/c)]=1717为质数,所以:(b/a)^2+(d/c)=17(b/a)^2-(d/c)=1求得(b/a)^2 = 9,即b/a=3, (d/c)=8;a = (b/a)^4 = 81; c= (d/c)^2 = 64b=3a=243; d=8c=512;d-b=269 欢迎追问