\(A=\frac{8^{18}+1}{8^{19}+1}\) VÀ \(B=\frac{8^{23}+1}{8^{23}+4}\)
Những câu hỏi liên quan
so sánh:\(A=\frac{8^{18}+1}{8^{19+1}}vaB=\frac{8^{23}+1}{8^{24+1}}\)
Tính giá trị biểu thức:
3) C= \(\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)\(\frac{5}{8}\)
4) D= \(\frac{1}{9}-\left|\frac{-5}{23}\right|-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{4}-\frac{7}{30}\)
3) C thiếu đề
4) \(D=\frac{1}{9}-\left|\frac{-5}{23}\right|-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{5}{23}+\frac{5}{23}-\frac{1}{9}-\frac{25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{1}{9}-\frac{5}{23}+\frac{5}{23}+\frac{-25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=0+0+\frac{125}{14}-\frac{7}{30}\)
\(D=\frac{913}{105}\)
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\(C=\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)
\(C=\frac{5}{18}+\frac{8}{19}-\frac{1}{3}+\frac{-5}{18}+\frac{11}{19}+\frac{1}{3}-\frac{5}{8}\)
\(C=\left(\frac{5}{18}+\frac{-5}{18}\right)+\left(\frac{8}{19}+\frac{11}{19}\right)+\left(\frac{-1}{3}+\frac{1}{3}\right)-\frac{5}{8}\)
\(C=0+1+0-\frac{5}{8}\)
\(C=\frac{3}{8}\)
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Bài 1 : So sánh A với B
a, \(A=\frac{8^{18}+1}{8^{19}+1}\)\(B=\frac{8^{23}+1}{8^{24}+1}\)
b, \(A=\frac{5^5}{5+5^2+5^3+5^4}\)
\(B=\frac{3^5}{3+3^2+3^3+3^4}\)
ta có A= \(\frac{8^{18}+1}{8^{19} +1}\)=> 8A=\(\frac{8^{19}+8}{8^{19}+1}\)= \(\frac{\left(8^{19}+1\right)+7}{8^{19}+1}\)=\(\frac{8^{19}+1}{8^{19} +1}\)+\(\frac{7}{8^{19}+1}\) =1+\(\frac{7}{8^{19}+1}\) =\(\frac{7}{8^{19}+1}\)
B= \(\frac{8^{23}+1}{8^{24}+1}\)=> 8B=\(\frac{8^{24}+8}{8^{24}+1}\)= \(\frac{\left(8^{24}+1\right)+7}{8^{24}+1}\)=\(\frac{8^{24}+1}{8^{24}+1}\)+\(\frac{7}{8^{24}+1}\) =1+\(\frac{7}{8^{24} +1}\)=\(\frac{7}{8^{24}+1}\)
vì \(8^{19}\)<\(8^{24}\)=> \(8^{19}\)+1 >\(8^{24}\)+1 => \(\frac{7}{8^{19}+1}\)<\(\frac{7}{8^{24}+1}\)=> A<B
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a) ta có \(8A=\frac{8^{19}+8}{8^{19}+1}=1+\frac{7}{8^{19}+1}\\ 8B=\frac{8^{24}+8}{8^{24}+1}=1+\frac{7}{8^{24}+1}\)
Vì \(8^{24}+1>8^{19}+1\\\frac{7}{8^{24}+1}< \frac{7}{8^{19}+1} \)
vậy 8A>8B nên A>B
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nhầm dấu
\(8^{19}\) +1<\(8^{24}\)+1=> \(\frac{7}{8^{19}+1}\)<\(\frac{7}{8^{24}+1}\)=> A<B
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A = \(\frac{\frac{-4}{9}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
Ta có : \(A=\frac{-\frac{4}{9}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
\(\Leftrightarrow A=\frac{-\left(\frac{4}{9}-\frac{4}{19}+\frac{4}{23}\right)}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
\(\Leftrightarrow A=\frac{-4\left(\frac{1}{9}-\frac{1}{19}+\frac{1}{23}\right)}{8\left(\frac{1}{5}-\frac{1}{19}+\frac{1}{23}\right)}\)
\(\Leftrightarrow A=-\frac{4}{8}=-\frac{1}{2}\)
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mik bi lam o cho \(\frac{-4}{9}\)la \(\frac{-4}{5}\)moi dung
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\(a,49\frac{8}{23}-\left(5\frac{7}{32}+14\frac{8}{23}\right)\)
\(b,71\frac{38}{45}-\left(43\frac{8}{45}-1\frac{17}{57}\right)\)
\(d,\left(19\frac{15}{8}:\frac{7}{12}-13\frac{1}{4}:\frac{7}{12}\right).\frac{4}{5}\)
\(\frac{\frac{-4}{5}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}\)
\(\frac{\frac{-4}{5}+\frac{4}{19}-\frac{4}{23}}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}=\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)\cdot\frac{1}{\frac{8}{5}-\frac{8}{19}+\frac{8}{23}}=\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)\cdot\frac{1}{-2\cdot\left(-\frac{4}{5}+\frac{4}{19}-\frac{4}{23}\right)}=-\frac{1}{2}\)
Tính giá trị biểu thức1.Afrac{1}{5}+frac{3}{17}-frac{4}{3}+left(frac{4}{5}-frac{3}{17}+frac{1}{3}right)-frac{1}{7}+left[frac{-14}{30}right]2.Bleft(frac{5}{8}-frac{4}{12}+frac{3}{2}right)-left(frac{5}{8}+frac{9}{13}right)-left[frac{-3}{2}right]+frac{7}{-15}3.Cfrac{5}{18}+frac{8}{19}-frac{7}{21}+left(frac{-10}{36}+frac{11}{19}+frac{1}{3}right)-frac{5}{8}4.Dfrac{1}{9}-left[frac{-5}{23}right]-left(frac{-5}{23}+frac{1}{9}+frac{25}{7}right)+frac{50}{14}-frac{7}{30}5.Efrac{1}{13}+left(frac{-5}{18}-frac...
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Tính giá trị biểu thức
\(1.A=\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\left(\frac{4}{5}-\frac{3}{17}+\frac{1}{3}\right)-\frac{1}{7}+\left[\frac{-14}{30}\right]\)
\(2.B=\left(\frac{5}{8}-\frac{4}{12}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left[\frac{-3}{2}\right]+\frac{7}{-15}\)
\(3.C=\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)
\(4.D=\frac{1}{9}-\left[\frac{-5}{23}\right]-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{14}-\frac{7}{30}\)
\(5.E=\frac{1}{13}+\left(\frac{-5}{18}-\frac{1}{13}+\frac{12}{17}\right)+\left(\frac{12}{17}+\frac{5}{18}+\frac{7}{5}\right)\)
\(6.F=\frac{15}{14}-\left(\frac{17}{23}-\frac{80}{87}+\frac{5}{4}\right)+\left(\frac{12}{17}-\frac{15}{14}+\frac{1}{4}\right)\)
\(7.G=\frac{1}{25}-\frac{4}{27}+\left(\frac{-23}{27}+\frac{-1}{25}-\frac{5}{43}\right)+\frac{5}{43}-\frac{4}{7}\)
\(8.H=\frac{4}{15}-\frac{23}{28}-\left(\frac{-23}{28}+\frac{-11}{15}-\frac{29}{27}\right)-\frac{2}{27}\)
\(9.K=\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{5}+\frac{3}{4}\)
\(10.L=\frac{7}{12}+\frac{15}{14}-\left(\frac{14}{22}+\frac{-1}{14}+\frac{5}{21}\right)-\frac{-5}{21}+\frac{3}{5}\)
yutyugubhujyikiu
bài 1
a. 5/18 + 8/19 - 7/21 + ( -10/36 + 11/19 + 1/3) - 5/8
b.1/13 + ( -5/18 - 1/13 + 12/17 ) - ( 12/17 - 5/18 + 7/5 )
c.15/14 - (17/23 - 80/87 + 5/4)+(17/23 - 15/14 + 1/4 )
d.1/25 - 4/27 + ( -23/27 + -1/25 - 5/43 ) + 5/43 - 4/7
bài 2
a. x +1/3 = 3/4
b. x - 2/5 = 5/7
c. -x - 2/3 = -6/7
d. 4/7 - x = 1/3
e. x+ 5/2 = -3/2
f. x + 5/6 = -1/12
GIÚP MÌNH VỚI Ạ MÌNH CẢM ƠN TRƯỚC
Bài 1:
a; \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{7}{21}\) + (- \(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{1}{3}\) -\(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{10}{36}\)) + (\(\dfrac{8}{19}\) + \(\dfrac{11}{19}\)) - (\(\dfrac{1}{3}\) - \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{5}{18}\)) + \(\dfrac{19}{19}\) - 0 - \(\dfrac{5}{8}\)
= 0 + 1 - \(\dfrac{5}{8}\)
= \(\dfrac{3}{8}\)
b; \(\dfrac{1}{13}\) + (\(\dfrac{-5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\)) - (\(\dfrac{12}{17}\) - \(\dfrac{5}{18}\) + \(\dfrac{7}{5}\))
= \(\dfrac{1}{13}\) - \(\dfrac{5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{12}{17}\) + \(\dfrac{5}{18}\) - \(\dfrac{7}{5}\)
= (\(\dfrac{1}{13}\) - \(\dfrac{1}{13}\)) + (\(\dfrac{12}{17}\) - \(\dfrac{12}{17}\)) + (-\(\dfrac{5}{18}\) + \(\dfrac{5}{18}\)) - \(\dfrac{7}{5}\)
= 0 + 0 + 0 - \(\dfrac{7}{5}\)
= - \(\dfrac{7}{5}\)
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Bài 1 c;
\(\dfrac{15}{14}\) - (\(\dfrac{17}{23}\) - \(\dfrac{80}{87}\) + \(\dfrac{5}{4}\)) + (\(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\))
= \(\dfrac{15}{14}\) - \(\dfrac{17}{23}\) + \(\dfrac{80}{87}\) - \(\dfrac{5}{4}\) + \(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\)
= (\(\dfrac{15}{14}-\dfrac{15}{14}\)) + (\(-\dfrac{17}{23}+\dfrac{17}{23}\)) - (\(\dfrac{5}{4}\) - \(\dfrac{1}{4}\)) + \(\dfrac{80}{87}\)
= 0 + 0 - 1 + \(\dfrac{80}{87}\)
= - \(\dfrac{7}{87}\)
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Bài 1 d;
\(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) + (-\(\dfrac{23}{27}\) + \(\dfrac{-1}{25}\) - \(\dfrac{5}{43}\)) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) - \(\dfrac{23}{27}\) - \(\dfrac{1}{25}\) - \(\dfrac{5}{43}\) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= (\(\dfrac{1}{25}\) - \(\dfrac{1}{25}\)) - (\(\dfrac{4}{27}\) + \(\dfrac{23}{27}\)) - (\(\dfrac{5}{43}\) - \(\dfrac{5}{43}\)) - \(\dfrac{4}{7}\)
= 0 - 1 - 0 - \(\dfrac{4}{7}\)
= \(\dfrac{-11}{7}\)
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Xem thêm câu trả lời
\(\frac{-4}{5}+\frac{8}{19}-\frac{4}{23}\)
\(\frac{8}{5}-\frac{8}{19}+\frac{8}{23}\)