We want to simplify a radical expression.
To do so we will assume that c>0, otherwise the given expression would not be defined.
4/sqrt(18c^2)
Let's recall the Multiplication Property of Square Rootssqrt(ab)=sqrt(a) * sqrt(b), for a≥ 0,b≥ 0
Let's use this property for our expression.
Now that we have simplified the factors as much as possible, we need to rationalize the denominator. We should multiply the numerator and denominator of the fraction by sqrt(2), the irrational part of the denominator.
