$$\left(\frac{y^3}{2}\right)^2 \cdot y^4 = \frac{\left(y^3\right)^2}{2^2} \cdot y^4 = \frac{y^{3 \cdot 2}}{4} \cdot y^4 = \frac{y^6}{4} \cdot y^4 = \frac{y^6 \cdot y^4}{4} = \frac{y^{6+4}}{4} = \frac{y^{10}}{4}$$
Ответ: y¹⁰/₄