Since 768 is an even number and 4 is a perfect square, I'm going to divide 768 by 4:
768 = 4 x 192
Since 193 is an even number and 4 is a perfect square, I'm going to divide 192 by 4:
768 = 4 x 4 x 48
Since 48 is an even number and 4 is a perfect square, I'm going to divide 48 by 4:
768 = 4 x 4 x 4 x 12
Since 12 is an even number and 4 is a perfect square, I'm going to divide 12 by 4:
768 = 4 x 4 x 4 x 4 x 3
So, the sqrt(768) = 2 x 2 x 2 x 2 x sqrt(3) = 16 x sqrt(3).