Sure. -243 is (-3)^5(negative 3 to the fifth power)
the exponent 3/5 means that we need to take fifth root and then raise the answer to the 3rd power(always, the top number is the power, the bottom number is the root)
so, fifth root of -243 will be -3 (fifth power and fifth root cancel each other)
(-3) to the 3rd power is -27