а) \[ (b^7)^2 \cdot b = b^{7 \times 2} \cdot b^1 = b^{14} \cdot b^1 = b^{14+1} = b^{15} \]
б) \[ m \cdot (m^9)^3 = m^1 \cdot m^{9 \times 3} = m^1 \cdot m^{27} = m^{1+27} = m^{28} \]
в) \[ (k^4)^3 \cdot k^5 = k^{4 \times 3} \cdot k^5 = k^{12} \cdot k^5 = k^{12+5} = k^{17} \]
г) \[ (y^5)^3 \cdot y^4 = y^{5 \times 3} \cdot y^4 = y^{15} \cdot y^4 = y^{15+4} = y^{19} \]
д) \[ (a^7)^3 : (a^4)^5 = a^{7 \times 3} : a^{4 \times 5} = a^{21} : a^{20} = a^{21-20} = a^1 = a \]
е) \[ (c^{10})^6 : ((c^7)^5 \cdot (c^3)^8) = c^{10 \times 6} : (c^{7 \times 5} \cdot c^{3 \times 8}) = c^{60} : (c^{35} \cdot c^{24}) = c^{60} : c^{35+24} = c^{60} : c^{59} = c^{60-59} = c^1 = c \]
Ответ: а) b¹⁵; б) m²⁸; в) k¹⁷; г) y¹⁹; д) a; е) c.