a)\(\frac{8^{14}}{4^{12}}=\frac{\left(2^3\right)^{14}}{\left(2^2\right)^{12}}=\frac{2^{42}}{2^{24}}=2^{18}\)
b)\(\frac{45^{10}.5^{10}}{75^{10}}=\frac{\left(3.15\right)^{10}.5^{10}}{\left(15.5\right)^{10}}=\frac{3^{10}.15^{10}.5^{10}}{15^{10}.5^{10}}=3^{10}\)
c)\(\left(-4+-\frac{2}{3}+1\frac{3}{4}\right).\frac{-12}{13}=\left(-4+\frac{-2}{3}+\frac{7}{4}\right).\frac{-12}{13}\)
=\(\left(\frac{-48}{12}+\frac{-8}{12}+\frac{21}{12}\right).\frac{-12}{13}=\frac{-48-8+21}{12}.\frac{-12}{13}\)
=\(\frac{-35}{12}.\frac{-12}{13}=\frac{35}{13}\)
d)\(\left(\frac{4}{15}+\frac{7}{20}-\frac{9}{20}\right).2,5+0,25=\left(\frac{16}{60}+\frac{21}{60}-\frac{27}{60}\right).\frac{5}{2}+\frac{1}{4}\)
\(=\frac{16+21-27}{60}.\frac{5}{2}+\frac{1}{4}=\frac{10}{60}.\frac{5}{2}+\frac{1}{4}\)
\(=\frac{1}{6}.\frac{5}{2}+\frac{1}{4}=\frac{5}{12}+\frac{1}{4}=\frac{5}{12}+\frac{3}{12}=\frac{8}{12}=\frac{2}{3}\)
A)\(\frac{8^{14}}{4^{12}}\)=\(\frac{\left(2^3\right)^{14}}{\left(2^2\right)^{12}}\)=\(\frac{2^{42}}{2^{24}}\)=\(2^{18}\)
B)\(\frac{45^{10}.5^{10}}{75^{10}}\)=\(\frac{\left(5.3^2\right)^{10}.5^{10}}{\left(5^2.3\right)^{10}}=\)\(\frac{5^{10}.3^{20}.5^{10}}{5^{20}.3^{10}}\)=\(\frac{5^{20}.3^{20}}{5^{20}.3^{10}}=\frac{3^{20}}{3^{10}}=3^{10}\)
C)\(\left(-4+-\frac{2}{3}+\frac{7}{4}\right).-\frac{12}{13}=\left(-\frac{48}{12}-\frac{8}{12}+\frac{21}{12}\right).-\frac{12}{13}=-\frac{35}{12}.-\frac{12}{13}=\frac{35}{13}\)
Nói j mà trả lời thì cái đó gọi là tự hỏi tự trả lời
