4. \((d^3)^5\cdot(d^2)^4\)

\((d^3)^5=d^{15}\), \((d^2)^4=d^8\).

\((d^3)^5\cdot(d^2)^4=d^{15}\cdot d^8=d^{15+8}=d^{23}\).

Ответ: \(d^{23}\)