原式=(x^2+x+4)/(x+2)=(x^2+4x+4-3x)/(x+2)=x+2-3x/(x+2),因它的值为整数,所以3x必为x+2的倍数,设3x=n*(x+2),n为整数,则有x=2n/(3-n),因x为正整数,所以,n=1,x=1或n=2,x=4.所以x的值是1或4.