Question

x-4 / x-2√x

 

√5a - 3√20a + √125a

 

срочно((

Answer 1

к сожалению, могу только второе.

$sqrt{5a}-3sqrt{20a}+sqrt{125a}=sqrt{5a}(1-3sqrt{4}+sqrt{25})=sqrt{5a} * (-10)=-10sqrt{5a}$

Answer 2

$frac{x-4}{x-2sqrt{x}}=\frac{(sqrt{x}-2)(sqrt{x}+2)}{sqrt{x}(sqrt{x}-2)}}=\ \frac{sqrt{x}+2}{sqrt{x}}$

 

$sqrt{5}a - 3sqrt{20}a + sqrt{125}a=sqrt{5}a-3sqrt{4*5}a + sqrt{25*5}a=\ sqrt{5}a-3*2sqrt{5}a +5sqrt{5}a=\sqrt{5}a-6sqrt{5}a +5sqrt{5}a=(1-6+5)sqrt{5}a=0$