(√x-2)/x-2÷(√x/x^3-2x^2)
=(√x-2)/(√x-2)^2 ÷ (√1/x^2-2x)
=1/(√x-2) * (√x^2 - 2x)
=1/(√x-2) *(√x(√x-2))
=√x
因为x - 2 > 0 若x = 4 则式子 = 2
(√x-2)/x-2÷(√x/x^3-2x^2)
=(√x-2)/(√x-2)^2 ÷ (√1/x^2-2x)
=1/(√x-2) * (√x^2 - 2x)
=1/(√x-2) *(√x(√x-2))
=√x
因为x - 2 > 0 若x = 4 则式子 = 2