y=（x²+11）/（x+1）的值为整数,则自然数X的和为

y=(x²-1+12)/(x+1)=[(x+1)(x-1)+12]/(x+1)=(x+1)(x-1)(x+1)+12/(x+1)=x-1+12/(x+1)则12/(x+1)是整数所以x+1是12的约数所以x+1=1,2,3,4,6,12所以x=0,1,2,3,5,11所以和=0+1+2+3+5+11=22