How do you simplify #sqrt20 * sqrt45 #? Algebra Radicals and Geometry Connections Multiplication and Division of Radicals 1 Answer Gerardina C. Jun 30, 2016 30 Explanation: #sqrt(20)=sqrt(4)*sqrt(5)=2sqrt(5)# #sqrt(45)=sqrt(5)*sqrt(9)=3sqrt(5)# so #sqrt(20)*sqrt(45)=2sqrt(5)*3sqrt(5)=6sqrt(25)=6*5=30# 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 982 views around the world You can reuse this answer Creative Commons License