Реши задания 16-20

16. 1) $(x^6)^2 = x^{6 \cdot 2} = x^{12}$ 2) $(-x^6)^4 = x^{6 \cdot 4} = x^{24}$ 3) $x^4 x^3 = x^{4+3} = x^7$ 4) $((x^3)^2)^5 = (x^{3 \cdot 2})^5 = (x^6)^5 = x^{6 \cdot 5} = x^{30}$ 5) $(x^{10})^3 \cdot (x^5)^4 = x^{10 \cdot 3} \cdot x^{5 \cdot 4} = x^{30} \cdot x^{20} = x^{30 + 20} = x^{50}$ 6) $(-x^6)^7 \cdot (-x^3)^3 : x^{15} = -x^{42} \cdot (-x^9) : x^{15} = x^{51} : x^{15} = x^{51-15} = x^{36}$ 17. 1) $\frac{5}{15} = \frac{1}{3}$ 2) $\frac{12}{18} = \frac{2}{3}$ 3) $\frac{27}{45} = \frac{3}{5}$ 4) $\frac{30}{48} = \frac{5}{8}$ 18. 1) $\frac{3}{7} = \frac{3 \cdot 2}{7 \cdot 2} = \frac{6}{14}$ 2) $\frac{8}{15} = \frac{8 \cdot 4}{15 \cdot 4} = \frac{32}{60}$ 19. 1) $a^5 a^3 = a^{5+3} = a^8$ 2) $(a^5)^3 = a^{5 \cdot 3} = a^{15}$ 3) $a^5 : a^3 = a^{5-3} = a^2$ 4) $(a^8)^4 : (a^2)^8 = a^{8 \cdot 4} : a^{2 \cdot 8} = a^{32} : a^{16} = a^{32-16} = a^{16}$ 20. 1) $6a - 15b = 3(2a - 5b)$ 2) $2a + ab = a(2 + b)$ 3) $7am + 7bn = 7(am + bn)$ 4) $4x^2 - 12xy = 4x(x - 3y)$ 5) $a^6 + a^2 = a^2(a^4 + 1)$ 6) $12m^2n - 4mn = 4mn(3m - 1)$ 7) $2x^2 - 4x^3 + 10x^4 = 2x^2(1 - 2x + 5x^2)$ 8) $10a^3b^2 - 15a^2b + 25ab^2 = 5ab(2a^2b - 3a + 5b)$