Question 64836
Method # 1
{{{( 3sqrt(a^7x^2)*sqrt(ax^2) )}}} 

{{{( 3sqrt(a^3a^3a^1x^2)*sqrt(ax^2) )}}} [factor the radicals]
.
 {{{( 3a^3x(sqrt(a)) (x(sqrt(a))) )}}} [find the square root of each radical]
.
{{{( 3a^3x^2(sqrt(a)) (sqrt(a)) )}}} [multiply]
.

 {{{( 3a^3x^2(a) )}}} [the square of a square root equals the number under the radical sign]
.
 {{{( 3a^4x^2 )}}}[simplify]
.
Method # 2

{{{( 3sqrt(a^7x^2)*sqrt(ax^2) )}}}multiply the radicals]
{{{( 3sqrt(a^8x^4)) )}}}
{{{( 3a^4x^2) )}}}