根号(55.5)^2-33.3^2=?

题目

根号(55.5)^2-33.3^2=?
根号55.5^2-33.3^2=?
题中的省略号代表80个相同的数（如5的省略号就代表80个5...）

答案

根号(55.5^2-33.3^2)
=根号[(55.5+33.3)(55.5-33.3)]
=根号(88.8*22.2)
=根号(44.4*2*22.2)
=根号(44.4*44.4)
=44.4