So sánh:A=\(\frac{13^{40}+2}{10^{40}-1}\)và B=\(\frac{13^{39}+2}{13^{39}-1}\)
Bài 1 :Thực hiện phép tính :
a) M =(\(\frac{-6}{13}+\frac{15}{26}-\frac{47}{39}-\frac{1}{78}\)) : (\(99\frac{17}{65}-100\frac{5}{52}+\frac{1}{130}\))
b) N = \(\frac{(\frac{3}{5}-0,435+\frac{1}{200}):\left(-0,04\right)}{30,75+\frac{1}{12}+3\frac{1}{6}}\)
c) P = (\(\frac{-5}{6}:\frac{-10}{11}\))+\(\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{\frac{-2}{12}-\frac{10}{24}+\frac{14}{39}}\)
Bài 2 : Thực hiện phép tính :V
a) P =\(\frac{\frac{1}{5}-\frac{1}{9}+\frac{1}{13}}{\frac{9}{5}-1+\frac{9}{13}}+\frac{\frac{10}{7}-\frac{10}{11}-\frac{10}{17}}{\frac{12}{7}-\frac{12}{11}-\frac{12}{17}}\)
b) Q = \(\frac{\frac{1}{14}-\frac{1}{30}-\frac{1}{46}}{\frac{2}{35}-\frac{2}{75}-\frac{2}{115}}:\frac{\frac{3}{8}-\frac{15}{17}+\frac{30}{31}}{\frac{1}{6}-\frac{20}{51}+\frac{40}{93}}\)
có rất nhiều câu dễ ở trong đề sao bạn Ko thử làm đi rồi câu nào khó lại hỏi
\(A=5,3:\left(5\frac{5}{28}-2\frac{13}{36}+1\frac{16}{63}\right)\)
\(B=\left(\frac{19}{10}\times\frac{19}{10}+\frac{39}{2}:\frac{13}{3}\right)\times\left(\frac{62}{75}-\frac{12}{75}\right)\)
So sánh A, 3^39 và 11^21 b, 67^7 và 16 ^ 12 c, 13^40 và 2^ 162
\(a\)\(3^{39}\)và \(11^{21}\)
\(3^{39}< 11^{21}\)vì
\(3^{39}< 3^{40}=3^{39}< \left(3^2\right)^{20}=9^{20}< 11^{21}\)
\(\Rightarrow3^{39}< 11^{29}\)
So sánh A, 3^39 và 11^21 b, 67^7 và 16 ^ 12 c, 13^40 và 2^ 162
a, 339 < 340 = (32)20=920<1121
b, chép đúng đề bài ko pn
c, 1340< 1640= (24)40= 2160<2162
a,21^10-1:200
b,39^20+39^13:40
c,2^60+5^30:41
d,2005^2007+2007^2005:2006
ai tích mình mình tích lại cho
ta có:
\(2^{60}+5^{30}\)
=\(\left(2^4\right)^{15}+\left(5^2\right)^{15}\)
=\(16^{15}+15^{15}\) luôn chia hết cho 16 + 25 = 41
\(\Rightarrow2^{60}+5^{30}\) chia hết cho 41 ( đpcm )
Bài 1 : So sánh
\(\left(\frac{1}{10}\right)^{15}\) và \(\left(\frac{3}{10}\right)^{20}\)
Bài 2 : So sánh
A = \(\left(\frac{13^{15}+1}{13^{16}+1}\right)\) và B = \(\left(\frac{13^{16}+1}{13^{17}+1}\right)\)
Bài 1:
Ta có:
\(\left(\frac{1}{10}\right)^{15}=\left(\frac{1}{5}\right)^{3.5}=\left(\frac{1}{125}\right)^5\)
\(\left(\frac{3}{10}\right)^{20}=\left(\frac{3}{10}\right)^{4.5}=\left(\frac{81}{10000}\right)^5\)
Lại có:
\(\frac{1}{125}=\frac{80}{10000}< \frac{81}{10000}\Rightarrow\left(\frac{1}{125}\right)^5< \left(\frac{81}{10000}\right)^5\)
\(\Rightarrow\left(\frac{1}{10}\right)^{15}< \left(\frac{3}{10}\right)^{20}\)
Bài 2:
Ta có:
\(A=\frac{13^{15}+1}{13^{16}+1}\Rightarrow13A=\frac{13^{16}+13}{13^{16}+1}=1+\frac{12}{13^{16}+1}\)
\(B=\frac{13^{16}+1}{13^{17}+1}\Rightarrow13B=\frac{13^{17}+13}{13^{17}+1}=1+\frac{12}{13^{17}+1}\)
Mà \(\frac{12}{13^{16}+1}>\frac{12}{13^{17}+1}\)
\(\Rightarrow1+\frac{12}{13^{16}+1}>1+\frac{12}{13^{17}+1}\)
\(\Rightarrow13A>13B\Rightarrow A>B\)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{\frac{-2}{12}-\frac{10}{24}+\frac{14}{39}}\) (x=0,5;y=3)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{-\frac{2}{12}-\frac{10}{24}+\frac{14}{39}}\)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{-\left(\frac{2}{12}+\frac{10}{24}-\frac{14}{39}\right)}\)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{-\frac{2}{3}\left(\frac{1}{4}+\frac{5}{8}-\frac{7}{13}\right)}\)
\(B=\frac{x}{y}+\frac{1}{-\frac{2}{3}}\)
\(B=\frac{x}{y}-\frac{3}{2}\)
Thế x = 0, 5 = 1/2 ; y = 3 ta được :
\(B=\frac{\frac{1}{2}}{3}-\frac{3}{2}=\frac{1}{6}-\frac{9}{6}=-\frac{8}{6}=-\frac{4}{3}\)
Ta có:\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{\frac{-2}{12}-\frac{10}{24}+\frac{14}{39}}\)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{-\left(\frac{2}{12}+\frac{10}{24}-\frac{14}{39}\right)}\)
\(B=\frac{x}{y}+\frac{\frac{1}{4}+\frac{5}{8}-\frac{7}{13}}{-\frac{2}{3}\left(\frac{1}{4}+\frac{5}{8}-\frac{7}{13}\right)}\)
\(B=\frac{x}{y}+\frac{1}{-\frac{2}{3}}\)(Do\(\frac{1}{4}+\frac{5}{8}-\frac{7}{13}\ne0\))
\(B=\frac{x}{y}-\frac{3}{2}\)
Thay x = 0,5; y = 3 vào B ta được:
\(B=\frac{0,5}{3}-\frac{3}{2}\)
\(B=\frac{1}{6}-\frac{3}{2}\)
\(B=\frac{1}{6}-\frac{9}{6}\)
\(B=-\frac{4}{3}\)
Vậy\(B=-\frac{4}{3}\)tại x = 0,5; y = 3
Linz
Thực hiện các phép tính:
a) \(\frac{5}{9}:\frac{13}{7}+\frac{5}{9}:\frac{13}{9}-1\frac{2}{3}\)
b) \(\left(15-6\frac{13}{18}\right):11\frac{1}{27}-2\frac{1}{8}:1\frac{11}{40}\)
a) \(\frac{5}{9}:\frac{13}{7}+\frac{5}{9}:\frac{13}{9}-1\frac{2}{3}\\ =\frac{5}{9}\cdot\frac{7}{13}+\frac{5}{9}\cdot\frac{9}{13}-\frac{5}{3}\\ =\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}\right)-\frac{5}{3}\\ =\frac{5}{9}\cdot\frac{16}{13}-\frac{5}{3}\\ =\frac{80}{117}-\frac{5}{3}\\ =\frac{80}{117}-\frac{195}{117}=\frac{-115}{117}\)
b) \(\left(15-6\frac{13}{18}\right):11\frac{1}{27}-2\frac{1}{8}:1\frac{11}{40}\\ =\left(\frac{270}{18}-\frac{121}{18}\right):\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\\ =\frac{149}{18}\cdot\frac{27}{298}-\frac{17}{8}\cdot\frac{40}{51}\\ =\frac{3}{4}-\frac{5}{3}\\ =\frac{9}{12}-\frac{20}{12}=\frac{-11}{12}\)
tính 2 cách
\(\frac{\frac{5}{22}+\frac{3}{13}-\frac{1}{2}}{\frac{4}{13}-\frac{2}{11}+\frac{3}{2}}\)
giúp mk nhé
\(=\frac{\frac{5}{11.2}+\frac{3}{13}-\frac{1}{2}}{\frac{4}{13}-\frac{1}{11}+\frac{3}{2}}=\frac{5}{\frac{2}{4}}=\frac{5}{\frac{1}{2}}\)