Indices

In the expression xn, n is called the exponent or index and x is called the base and xn is read as ‘x to the power of n’ or ‘x raised to the power n’.
eg,
1. 3⁶ = 3 × 3 × 3 × 3 × 3 × 3 = 729
4³ = 4 × 4 × 4 = 64
The expression (xm)n is read as ‘x raised to the power m whole raised to the power n’.
2. (2⁴)³ = (16)³ = 212
The expression is read as ‘x raised to the power m power n’.
3. = 264
Hence, (x^m)n¹

Surds

If n is a positive integer and ‘a’ is a positive rational number (a > 0), then ⁿ√^ais called a surd of order n or nth order surd ⁿ√^aif is an irrational number.