How do you simplify square Root of 72 Minus Square Root of 18?

## = color(green)(3sqrt2##

The square root of ##72## minus square root of ##18## can be expressed as ##sqrt72- sqrt18##

Now, ##sqrt72 = sqrt(3^2 * 2^2 *2) = 6sqrt2##

##sqrt18 = sqrt(3^2*2) = 3sqrt2##

##6sqrt2- 3sqrt2 = color(green)(3sqrt2##