A perfect square is the product of any number that is multiplied by itself, such as 81, which is the product of 9 x 9. To simplify a perfect square under a radical, simply remove the radical sign and write the number that is the square root of the perfect square.  For example, 121 is a perfect square because 11 x 11 is 121. Thus, you can simplify sqrt(121) to 11, removing the square root symbol. To make this process easier, you should memorize the first twelve perfect squares: 1 x 1 = 1, 2 x 2 = 4, 3 x 3 = 9, 4 x 4 = 16, 5 x 5 = 25, 6 x 6 = 36, 7 x 7 = 49, 8 x 8 = 64, 9 x 9 = 81, 10 x 10 = 100, 11 x 11 = 121, 12 x 12 = 144 A perfect cube is the product of any number that is multiplied by itself twice, such as 27, which is the product of 3 x 3 x 3. To simplify a radical expression when a perfect cube is under the cube root sign, simply remove the radical sign and write the number that is the cube root of the perfect cube. For example, 343 is a perfect cube because it is the product of 7 x 7 x 7. Therefore, the cube root of the perfect cube 343 is simply 7.

How would you rephrase that briefly using Indonesian?
Sederhanakan semua akar yang mengandung bilangan kuadrat sempurna. Sederhanakan semua akar yang mengandung bilangan pangkat tiga sempurna.