Simplify (1/(y^-1*y^2))^(3/4)

${(\frac{1}{y^{- 1} \cdot y^{2}})}^{\frac{3}{4}}$

Multiply $y^{- 1}$ by $y^{2}$ by adding the exponents.

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

${(\frac{1}{y^{- 1 + 2}})}^{\frac{3}{4}}$

Add $- 1$ and $2$ .

${(\frac{1}{y^{1}})}^{\frac{3}{4}}$

Simplify $y^{1}$ .

${(\frac{1}{y})}^{\frac{3}{4}}$

Apply the product rule to $\frac{1}{y}$ .

$\frac{1^{\frac{3}{4}}}{y^{\frac{3}{4}}}$

One to any power is one.

$\frac{1}{y^{\frac{3}{4}}}$