an为等差数列,易知a5-a3=a3-a1=2d所以5b1*d^4-3b1*d^2=3b1*d^2-b1若b1=0,则可知a1=0,d=0若b1不等于0则5d^4-6d^2+1=0因为d不等于1,所以d=-1或者d=√5/5或者d=-√5/5当d=-1的时候,易求a1=-1...