How do you simplify: Square root 18? Algebra Radicals and Geometry Connections Simplification of Radical Expressions 1 Answer Don't Memorise Jul 21, 2015 #=color(blue)(3sqrt2# Explanation: Prime factorise the number( express 18 as a product of prime numbers ): #sqrt(18) = sqrt(3*3*2)# #=sqrt(3^2*2)# #=3sqrt2# Answer link Related questions How do you simplify radical expressions? How do you simplify radical expressions with fractions? How do you simplify radical expressions with variables? What are radical expressions? How do you simplify #root{3}{-125}#? How do you write # ""^4sqrt(zw)# as a rational exponent? How do you simplify # ""^5sqrt(96)# How do you write # ""^9sqrt(y^3)# as a rational exponent? How do you simplify #sqrt(75a^12b^3c^5)#? How do you simplify #sqrt(50)-sqrt(2)#? See all questions in Simplification of Radical Expressions Impact of this question 100848 views around the world You can reuse this answer Creative Commons License