Evaluate without using a calculator. 64^-5/6

### 3 Answers | Add Yours

To simplify without a calculator, write the base (in this case 64) in its lowest form. If you cannot go straight to the prime base consider that `64 = 8 times 8 or 8^2`

We know that `8 = 2^3` so `2^3 times 2^3 = 2^6`

`therefore 64^(-5/6)`

`= (2^6)^(-5/6)`

The rules of exponents tells us `(a^m)^n = a^(m times n)`

`therefore = 2^(-30/6)`

simplify the `30/6`

`= 2^(-5)`

Rewrite using positive exponents:

`= 1/2^5`

`= 1/32`

**The answer is `2^-5`**

**` or 1/2^5 or 1/32` as a final answer**

`(64)^-(5/6)=1/root(6)(64^5)=1/root(6)((2^6)^5)=1/root(6)((2^5)^6)=1/2^5=1/32`

We know

`64=2xx2xx2xx2xx2xx2`

`64=2^6`

`(x^m)^n=x^(mxxn)`

`Thus`

`(64)^(-5/6)=(2^6)^(-5/6)`

`(2)^(-6xx5/6)=(2)^(-5)`

`x^(-m)=1/x^n`

`2^(-5)=1/2^5`

`=1/32`

### Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes