What is the square root of 45 times the square root of -5? Algebra Radicals and Geometry Connections Multiplication and Division of Radicals 1 Answer bp Sep 8, 2015 15 i Explanation: #sqrt45 * sqrt-5 -> sqrt45*i sqrt5 ->i sqrt(45*5) ->i sqrt225 ->15 i# 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 1642 views around the world You can reuse this answer Creative Commons License