Question 106890
1/ Square root of 5 minus the square root of 2

if we have:

{{{1/sqrt(5) }}}– {{{sqrt(2))}}}      multiply both terms  by {{{sqrt(5)}}}

{{{1 }}}– {{{sqrt(2)sqrt(5)}}}  

Since {{{a = 2}}} and {{{b = 5}}} both are positive real numbers, we can use the following are some property of square root function.  

{{{sqrt(a)sqrt(b) = sqrt(ab)}}}

or

{{{sqrt(2)sqrt(5 ) = sqrt(10)}}}

Then we have

{{{1 }}}– {{{sqrt(2)sqrt(5)}}} = {{{1 }}}– {{{sqrt(10)}}} = {{{1 - 1.78}}} = {{{-.78}}}



2.
in case you mean:

{{{1/(sqrt(5) - sqrt(2)) = 1/(2.24- 1.19) = 1/1.05 = 0.95}}}