观察题目,可用借助于整体思想,设=a,=b,进行替换,加以解答.
【解析】
设=a,=b.则,.
又4==a3b3,
∴x=a2b-ab2,x2=a4b2-2a3b3+a2b4,
故原式=x(x2+12),
=(a2b-ab2)(a4b2-2a3b3+a2b4+12),
=(a2b-ab2)(a4b2-8+a2b4+12),
=(a2b-ab2)(a4b2+a2b4+4),
=ab(a-b)a2b2(a2+b2+ab),
=a3b3(a3-b3),
=,
=4×2=8.
则其算术平方根是2.
故答案为:2.