Evaluate: (y^4)/(y^5)

Expression: $\frac{y^{4}}{y^{5}}$

Apply exponent rule $\frac{x^{a}}{x^{b}}=x^{a-b}$

$=y^{4-5}$

Subtract the numbers: $ 4-5=-1$

$=y^{-1}$

Apply exponent rule $a^{-1}=\frac{1}{a}$

$=\frac{1}{y}$