a: \(4^8\cdot2^{20}=\left(2^2\right)^8\cdot2^{20}=2^{16}\cdot2^{20}=2^{16+20}=2^{36}\)

\(9^{12}\cdot27^5\cdot81^4=\left(3^2\right)^{12}\cdot\left(3^3\right)^5\cdot\left(3^4\right)^4\)

\(=3^{24}\cdot3^{15}\cdot3^{16}=3^{24+15+16}=3^{55}\)

\(64^3\cdot4^5\cdot16^2=\left(4^3\right)^3\cdot4^5\cdot\left(4^2\right)^2=4^9\cdot4^5\cdot4^4=4^{9+5+4}=4^{18}\)

b: \(25^{20}\cdot125^4=\left(5^2\right)^{20}\cdot\left(5^3\right)^4=5^{40}\cdot5^{12}=5^{52}\)

\(x^7\cdot x^4\cdot x^3=x^{7+4+3}=x^{14}\)

\(3^6\cdot4^6=\left(3\cdot4\right)^6=12^6\)

c: \(8^4\cdot2^3\cdot16^2=\left(2^3\right)^4\cdot2^3\cdot\left(2^4\right)^2\)

\(=2^{12}\cdot2^3\cdot2^8=2^{23}\)

\(y\cdot y^7=y^{1+7}=y^8\)

\(2^3\cdot2^2\cdot8^3=2^5\cdot\left(2^3\right)^3=2^5\cdot2^9=2^{5+9}=2^{14}\)

\(x.x^2.x^3...x^{49}=x^{1+2+3+...+49}=x^{1225}\)

a) 2² . 3² . 4²

b) 2² . 6 . 3² . 15 . 5²

cảm ơn dù ko bt đúng sai

5^12*7-5^11*10

=5^12*7-5^11*(5.2)

=5^12*7-5^12*2

=5^12*(7-2)

=5^12*5

=5^13

\(5^{12}.7-5^{11}.10=5^{11}.\left(5.7-10\right)=5^{11}.25=5^{11}.5^2=5^{13}\)

a) 2.4.8.8 = 2.2.2.2.2.2.2.2.2 = 2 9

b) x.x.x.x.x = x 5

Bài 6: 

a: \(2^{27}=8^9\)

\(3^{18}=9^9\)

b: Vì \(8^9< 9^9\)

nên \(2^{27}< 3^{18}\)

cảm ơn nha