Question 110218
If we let {{{y=sqrt(7x)}}} we get


{{{7y+5y}}}


Now combine like terms


{{{7y+5y=(7+5)y=12y}}}



Now plug {{{y=sqrt(7x)}}} back in to get


{{{12y=12*sqrt(7x)}}}


So in other words, {{{7*sqrt(7x)+5*sqrt(7x)=12*sqrt(7x)}}}