How do you simplify #x *sqrt 18 - 3 * sqrt(8x^2)#? Algebra Radicals and Geometry Connections Multiplication and Division of Radicals 1 Answer Lovecraft Sep 18, 2015 #xsqrt(18) - 3sqrt(8x^2) = -3xsqrt(2)# Explanation: #xsqrt(18) - 3sqrt(8x^2) = # #xsqrt(9*2) - 3sqrt(4*2*x^2)=# #3xsqrt(2)-6xsqrt(2)=# #-3xsqrt(2)# (That is, if and only if, #x >=0#, if not #3xsqrt(2)-6|x|sqrt(2)#, because everything that comes out of a root must be positive or a zero.) 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 1361 views around the world You can reuse this answer Creative Commons License