Question 140862
Don't you mean the 27 is INSIDE the radical sign?  And the 12 also??


Like {{{sqrt(27) + sqrt(12)}}}
{{{sqrt(9)*sqrt(3) + sqrt(4)*sqrt(3)}}}
{{{3*sqrt(3) +2*sqrt(3) }}}
{{{5 * sqrt(3) }}}


For a detailed explanation of this see my website by clicking on my tutor name "rapaljer" anywhere in algebra.com.  Take the first link which is "Basic, Intermediate, or College Algebra: One Step at a Time."  Click on "Basic Algebra", then "Chapter 5", and look for Section 5.03 Adding and Subtracting Square Roots.  MY explanations here are for students who don't understand the traditional textbooks.  


R^2