Решение №1

1. $$m^5 cdot m^3 = m^{5+3} = m^8$$
2. $$x cdot x^6 = x^{1+6} = x^7$$
3. $$a^4 cdot a^4 = a^{4+4} = a^8$$
4. $$5^9 cdot 5^4 = 5^{9+4} = 5^{13}$$
5. $$y^3 cdot y^8 cdot y^5 = y^{3+8+5} = y^{16}$$
6. $$c^7 cdot c cdot c^2 = c^{7+1+2} = c^{10}$$
7. $$(m - n)^8 cdot (m - n)^3 = (m - n)^{8+3} = (m - n)^{11}$$
8. $$z^5 cdot z cdot z^{12} cdot z^2 = z^{5+1+12+2} = z^{20}$$
9. $$(x - 2)^4 cdot (x - 2)^9 = (x - 2)^{4+9} = (x - 2)^{13}$$