5.9^2:8=2x
Cho E=2^15.0,5^5+3.2^10/2^11.2^3-2^15:2^3 Cho F=2.6^7+6^8/2^5.9^4-2.3^7+3^8 Cho G=4^5.9^4-2.6^9/2^10.3^8+6^8.20
Tính:
a) \(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
b) T=\(\dfrac{5^{16}.27^7}{125^5.9^{11}}\)
a: \(=\dfrac{2^{10}\cdot3^8-2^{10}\cdot3^9}{2^{10}\cdot3^8+2^{10}\cdot3^8\cdot5}=\dfrac{2^{10}\cdot3^8\left(1-3\right)}{2^{10}\cdot3^8\left(1+5\right)}=\dfrac{-2}{6}=\dfrac{-1}{3}\)
b: \(=\dfrac{5^{16}\cdot3^{21}}{5^{15}\cdot3^{22}}=\dfrac{5}{3}\)
2/3.5+4/5.9+8/9.17
Không chép lại đầu bài nha!
=\(\frac{5-3}{3.5}+\frac{9-5}{5.9}+\frac{17-9}{9.17}\)
=\(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}\)
=\(\frac{1}{3}-\frac{1}{11}\)
=\(\frac{8}{33}\)
a,Tính M= \(-\dfrac{4}{1.5}-\dfrac{4}{5.9}-..........-\dfrac{4}{\left(n+4\right).n}\)
b, Tìm x biết:
-4x ( x-5)-2x(8-2x)=-3
\(M=-\left(\dfrac{4}{1.5}+\dfrac{4}{5.9}+...+\dfrac{4}{n\left(n+4\right)}\right)\\ =-\left(1-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{9}+...+\dfrac{1}{n}-\dfrac{1}{n+4}\right)\\ =-\left(1-\dfrac{1}{n+4}\right)\\ =-\left(\dfrac{n+3}{n+4}\right)\)
\(-4x\left(x-5\right)-2x\left(8-2x\right)=-3\\ \Rightarrow-4x^2+20x-16x+4x^2=-3\\ \Rightarrow4x=-3\\ \Rightarrow x=-\dfrac{3}{4}\)
a) \(M=-\dfrac{4}{1.5}-\dfrac{4}{5.9}-...-\dfrac{4}{\left(n-4\right)n}\)
⇔ \(M=-\left(\dfrac{4}{1.5}+\dfrac{4}{5.9}+...+\dfrac{4}{\left(n-4\right)n}\right)\)
⇔ \(M=-\left(1-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{9}+...+\dfrac{1}{n-4}-\dfrac{1}{n}\right)\)
⇔ \(M=-\left(1-\dfrac{1}{n}\right)\)
⇔ \(M=-\dfrac{n-1}{n}\)
b) - 4x(x - 5) - 2x(8 - 2x) = -3
⇔ -4x2 + 20x - 16x + 4x2 = -3
⇔ 4x = -3
⇔ x = \(-\dfrac{3}{4}\)
4^5.9^4-2.6^9/2^10.3^8+6^10
\(\dfrac{4^5\cdot9^4-2\cdot6^9}{2^{10}\cdot3^8+6^{10}}\)
\(=\dfrac{2^{10}\cdot3^8-2^{10}\cdot3^9}{2^{10}\cdot3^8+2^{10}\cdot3^{10}}\)
\(=\dfrac{2^{10}\cdot3^8\left(1-3\right)}{2^{10}\cdot3^8\left(1+3^2\right)}=-\dfrac{2}{10}=-\dfrac{1}{5}\)
\(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^{10}}\)
\(=\dfrac{\left(2^2\right)^5.\left(3^2\right)^4-2.\left(2.3\right)^9}{2^{10}.3^8+\left(2.3\right)^{10}}\)
\(=\dfrac{2^{10}.3^8-2.2^9.3^9}{2^{10}.3^8+2^{10}.3^{10}}\)
\(=\dfrac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8.\left(1+3^2\right)}\)
\(=\dfrac{2^{10}.3^8.\left(1-3\right)}{2^{10}.3^8.10}\)
\(=\dfrac{-2}{10}\)
\(=\dfrac{-1}{5}\)
thực hiện phép tính
A=\(\frac{2^{12}.3^4-4^5.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)
B=\(\frac{8^5.5^8-2^5.10^9}{2^{16}.5^7+20^8}\)
C=\(\frac{4^5.9^4-2.6^4}{2^{10}.3^8+6^8.2^0}\)
ban nao co chuyen shin ko cho minh muon minh giai cho 10 bai nhu the i love pac pac
\(A=\frac{2^{12}.3^4-4^5.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)
\(A=\frac{2^{12}.3^4-2^{10}.3^4}{2^{12}.3^6+2^{12}.3^5}\)
\(A=\frac{2^{10}.3^4\left(2^2-1\right)}{2^{10}.3^4\left(2^2.3^2+2^2.3\right)}\)
\(A=\frac{2^2-1}{2^2.3^2+2^2.3}\)
\(A=\frac{4-1}{36+12}\)
\(A=\frac{3}{48}=\frac{1}{16}\)
10.6^9-4^5.9^4/2^10.3^8+6^8.28
\(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
\(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}=\dfrac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}=\dfrac{2^{10}.3^8\left(1-3\right)}{2^{10}.3^8\left(1-5\right)}=\dfrac{-2}{-4}=\dfrac{1}{2}\)
5 + 5.9+5.9^2+5.9^3+.....+5.9^99