How do you simplify #21/sqrt7#? Algebra Radicals and Geometry Connections Multiplication and Division of Radicals 1 Answer Don't Memorise Feb 28, 2016 #=color(blue)(3sqrt7# Explanation: #21/sqrt7# Rationalising the denominator: #21/sqrt7= (21 xx color(blue)(sqrt7))/(sqrt7 xx color(blue)(sqrt7# #=(21sqrt7)/7# #=(cancel21sqrt7)/cancel7# #=color(blue)(3sqrt7# Answer link Related questions How do you simplify #\frac{2}{\sqrt{3}}#? How do you multiply and divide radicals? How do you rationalize the denominator? What is Multiplication and Division of Radicals? How do you simplify #7/(""^3sqrt(5)#? How do you multiply #(sqrt(a) +sqrt(b))(sqrt(a)-sqrt(b))#? How do you rationalize the denominator for #\frac{2x}{\sqrt{5}x}#? Do you always have to rationalize the denominator? How do you simplify #sqrt(5)sqrt(15)#? How do you simplify #(7sqrt(13) + 2sqrt(6))(2sqrt(3)+3sqrt(6))#? See all questions in Multiplication and Division of Radicals Impact of this question 2725 views around the world You can reuse this answer Creative Commons License