√x-2 √X

问题描述:

√x-2 √X
------ ÷ --------
x-2 √x的三次方减2x的2次方

=[√(x-2)/(x-2)]×[√x²(x-2)/√x]
=[√(x-2)/(x-2)]×√[x(x-2)]
=√[(x-2)x(x-2)]/(x-2)
=√[x(x-2)²]/(x-2)
=(x-2)√x/(x-2)
=√x