2. Упростить выражение:
1) $$\sqrt[28]{a^7}$$
$$\sqrt[28]{a^7} = (a^7)^{\frac{1}{28}} = a^{\frac{7}{28}} = a^{\frac{1}{4}} = \sqrt[4]{a}$$
2) $$\sqrt[5]{b^3\sqrt[4]{b^3}}$$
$$\sqrt[5]{b^3\sqrt[4]{b^3}} = \sqrt[5]{b^3 \cdot b^{\frac{3}{4}}} = (b^{3+\frac{3}{4}})^{\frac{1}{5}} = (b^{\frac{15}{4}})^{\frac{1}{5}} = b^{\frac{15}{20}} = b^{\frac{3}{4}} = \sqrt[4]{b^3}$$
3) $$\sqrt[6]{m^6}, y \leq 0$$;
$$\sqrt[6]{m^6} = |m|$$
Т.к. $$y \leq 0$$, то $$\sqrt[6]{m^6} = -m$$
Ответ: 1) $$\sqrt[4]{a}$$; 2) $$\sqrt[4]{b^3}$$; 3) $$-m$$