BT1: Tìm n thuộc Z
\(\frac{1}{9}.27^n=3^n\)
\(\left(\frac{3}{7}\right)^n=\frac{81}{2401}\)
BT2: Tính
\(\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
\(\frac{2.8^4.27^2+4.6^9}{2^7.6^6+2^7.40.9^4}\)
Rút gọn các biểu thức sau :
A=\(\frac{2.8^4.27^2+4.6^9}{2^7.6^7+2^7.40.9^4}\)
B=\(\frac{\left(\frac{2}{3}\right)^3.\left(-\frac{3}{4}\right)^2.\left(-1\right)^5}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
Rút gọn
A=\(\frac{2.8^4.27^2+4.6^9}{2^7.6^7+2^7.40.9^4}\)
B=\(\frac{\left(\frac{2}{3}\right)^2.\left(-\frac{3}{4}\right)^2.\left(-1\right)^5}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
Rút gọn
A=\(\frac{2.8^4.27^2+4.6^9}{2^7.6^7+2^7.40.9^4}\)
B=\(\frac{\left(\frac{2}{3}\right)^2.\left(-\frac{3}{4}\right)^2.\left(-1\right)^5}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
Tính:
\(A=\frac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right)^2}\)
\(B=\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(C=\frac{4^5.9^{4-2.6^9}}{2^{10}.3^8+6^8.20}\)
b. \(\dfrac{8^2.6^3}{9^2.16^2}\)
c. \(\dfrac{\left(0,15\right)^4}{\left(0,5\right)^5}\)
d. \(\left(\dfrac{3}{4}\right)^3\). \(\left(\dfrac{16}{9}\right)^3\)
Tính:
\(a.\frac{8^5.\left(-5\right)^8+\left(-2\right)^5.10^9}{2^{16}.5^7+20^8}\)
\(b.\frac{\left(-0,25\right)^{-5}.9^4.\left(-2\right)^{-3}-2^{-2}.6^9}{2^9.3^6+6^6.40}\)
\(c.\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
Bài 1 Thưc hiện phép tính ( tính nhanh nếu có thể)
a)\(\frac{-1}{24}-\left[\frac{1}{4}-\left(\frac{1}{2}-\frac{7}{8}\right)\right]\)
b)\(\left(\frac{5}{7}-\frac{7}{5}\right)-\left[\frac{1}{2}-\left(\frac{-2}{7}-\frac{1}{10}\right)\right]\)
C)\(\left(\frac{-1}{2}\right)-\left(\frac{-3}{5}\right)+\left(\frac{-1}{9}\right)+\frac{1}{17}-\left(\frac{-2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
d)\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5-\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
1.Thực hiện phép tính:(hepl me)
a)\(4\frac{5}{9}:\left(\frac{-5}{7}\right)+\frac{49}{9}:\left(\frac{-5}{7}\right)\)
b)\(\left(\frac{-3}{5}+\frac{4}{9}\right):\frac{7}{11}+\left(\frac{-2}{5}+\frac{5}{9}\right):\frac{7}{11}\)
c)\(\left(\frac{3}{4}\right)^4\times\left(\frac{8}{9}\right)^2\)
d)\(\left(\frac{-3}{5}\right)^6\times\left(-\frac{5}{3}\right)^5\)
e)\(\frac{8^{14}}{4^4\times64^5}\)
f)\(\frac{9^{10}\times27^7}{81^7\times3^{15}}\)