-24.5+6.[(-15)-9]
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\(3^6\cdot45^4-15^{13}\cdot5^{-9}\)
\(=3^6\cdot\left(3^2\cdot5\right)^4-\left(3\cdot5\right)^{13}\cdot5^{-9}\)
\(=3^6\cdot3^8\cdot5^4-3^{13}\cdot5^{13}\cdot5^{-9}=3^{14}\cdot5^4-3^{13}\cdot5^4=3^{13}\cdot5^4\left(3-1\right)=3^{13}\cdot5^4\cdot2\)
\(27^4\cdot25^3+45^6\)
\(=\left(3^3\right)^4\cdot\left(5^2\right)^3+\left(3^2\cdot5\right)^6\)
\(=3^{12}\cdot5^6+3^{12}\cdot5^6=2\cdot3^{12}\cdot5^6\)
Ta có: \(\frac{3^6\cdot45^4-15^{13}\cdot5^{-9}}{27^4\cdot25^3+45^6}\)
\(=\frac{3^{13}\cdot5^4\cdot2}{2\cdot3^{12}\cdot5^6}\)
\(=\frac{3}{5^2}=\frac{3}{25}\)
\(\frac{3}{1.4}+\frac{6}{4.10}+\frac{9}{10.19}+\frac{12}{19.31}+\frac{15}{31.46}+\frac{18}{46.64}\)
\(=1-\frac{1}{4}+\frac{1}{4}-\frac{1}{10}+\frac{1}{10}-\frac{1}{19}+\frac{1}{19}-\frac{1}{31}+\frac{1}{31}-\frac{1}{46}+\frac{1}{46}-\frac{1}{64}\)
\(=1-\frac{1}{64}=\frac{63}{64}\)
Bạn ko hiểu chỗ nào là phải hỏi mình ngay nhé!
\(\frac{3}{1.4}+\frac{6}{4.10}+\frac{9}{10.19}+\frac{12}{19.31}+\frac{15}{31.46}+\frac{18}{46.64}\)
\(=1-\frac{1}{4}+\frac{1}{4}-\frac{1}{10}+\frac{1}{10}-\frac{1}{19}+\frac{1}{19}-\frac{1}{31}+\frac{1}{31}-\frac{1}{46}+\frac{1}{46}-\frac{1}{64}\)
\(=1-\frac{1}{64}\)
\(=\frac{63}{64}\)
Ở câu a) số mũ lúc nào cug dương mà bạn ( 45-10 = 4510). Nếu số mũ là dương thì:
a)\(\frac{45^{10}.5^{20}}{75^{15}}\)
= \(\frac{\left(3^2.5\right)^{10}.5^{20}}{\left(3.5^2\right)^{15}}\)
= \(\frac{3^{20}.5^{10}.5^{20}}{3^{15}.5^{30}}\)
= \(\frac{3^{20}.5^{30}}{3^{15}.5^{30}}\)
= \(\frac{3^5.1}{1.1}\)
= \(\frac{243}{1}\)
= 243
b)\(\frac{2^{15}.9^4}{6^6.8^2}\)
= \(\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^6.\left(2^3\right)^2}\)
= \(\frac{2^{15}.3^8}{2^6.3^6.2^6}\)
= \(\frac{2^{15}.3^8}{2^{12}.3^6}\)
= \(\frac{2^3.3^2}{1.1}\)
= \(\frac{8.9}{1}\)
= \(\frac{72}{1}\)
= 72
45 x 94 - 2 x 69=6718464 - 20155392 = -13436928
210 x 38 + 68 x 20=6718464+33592320=40310784
=-120+6*[-24]
=-144-120
=-264
\(-24.5+6.\left[\left(-15\right)-9\right]\\ =-24.5+6.\left(-24\right)\\ =-24.\left(5+6\right)\\ =-24.11\\ =-264\)