In 5² what is the exponent?

Which is equivalent to 3⁴

 $\left(-x\right)\left(-x\right)\left(-x\right)$  is equivalent to which expression.

 $-x^3$ is equivalent to which expression?

 $-8\left(z\right)\left(z\right)\left(z\right)\left(z\right)$ is equivalent to which expression?

 $-4\cdot-4\cdot-4\cdot-4$ is equivalent to which expression?

 $\left(-6y\right)\left(-6y\right)\left(-6y\right)$ is equivalent to which expression?

 $\left(-8z\right)\left(-8z\right)\left(-8z\right)\left(-8z\right)$ is equivalent to which expression?