(999..9)1999个9加1999...9(1999个9)的平方根怎样算?

问题描述:

(999..9)1999个9加1999...9(1999个9)的平方根怎样算?
求求你们!

999...9(1999个9)*999...9(1999个9)+1999...9(1999个9)
=999...9^2(1999个9)+1999...98(1999-1个9)+1
=999...9^2(1999个9)+2*999...9(1999个9)*1+1^2
=(999...9(1999个9)+1)^2
=1000...0^2(1999个0)
=1000...0(2*1999个0)