exponents

If $Pe^x = Qe^{-x}$ for all real values of $x$, which one of the following statements is true?

If $$pqr \ne 0$$ and $${p^{ - x}} = {1 \over q},{q^{ - y}} = {1 \over r},\,{r^{ - z}} = {1 \over p},$$ what is the value of the product $$𝑥𝑦𝑧$$?

X is a 30 digit number starting with the digit 4 followed by the digit 7. Then the number X³ will have