46) $$(u^6-r^3)^2 = (u^6)^2 - 2 \cdot u^6 \cdot r^3 + (r^3)^2 = u^{12} - 2u^6r^3 + r^6 $$
Ответ: $$u^{12} - 2u^6r^3 + r^6$$