Question 948403
a:


The expressions inside the square roots must be non-negative.
{{{x>=-20}}}  and {{{x<=-5}}}.
The x values in both of those are {{{highlight(-20<=x<=-5)}}}.  That is the domain.



b:


The average rate of change on the described interval of g.
{{{(2(a+h)^2-5(a+h)-(2(a)^2-5(a)))/((a+h)-a)}}}


{{{(2(a^2+2ah+h^2)-5a-5h-(2a^2-5a))/h}}}


{{{(2a^2+4ah+2h^2-5a-5h-2a^2+5a)/h}}}
Look for the additive inverses in numerator.


{{{(4ah+2h^2-5h)/h}}}


{{{(h/h)(4a+2h-5)}}}


{{{highlight(4a+2h-5)}}}


Keep track of the variables and expressions in each step.