2^2 means 2 multiplied by 2 equals 4. 2^3 means 2 multiplied by 2 and then multiplied by 2 again which equals 8. Similarly, if you multiply c with itself 4 times you will get the value of .
Similarly we do the same thing for ()³. ()³ is multiplied with itself and then multiplied with itself again. If there are two powers on a number, we just multiply the powers and replace the two value.