Question 793236
You cannot take the square root of a negative number. Therefore, {{{2x-10}}} must be 0 or positive, ie 


{{{2x-10>=0}}}


{{{2x>=10}}}


{{{x>=10/2}}}


{{{x>=5}}}


So any number that is 5 or larger for x will make {{{sqrt(2x-10)}}} produce a real number.