\(\frac{1}{2}+\frac{2}{8}+\frac{3}{28}+\frac{4}{77}+\frac{5}{176}\)
Tính bằng cách thuận tiện nhất :
A = \(\frac{1}{2}+\frac{2}{8}+\frac{3}{28}+\frac{4}{77}+\frac{5}{176}\)
TÍNH GIÁ TRỊ CỦA BIỂU THỨC:
\(\frac{1}{2}\)+\(\frac{2}{8}\)+\(\frac{3}{28}\)+\(\frac{4}{77}\)+\(\frac{5}{176}\)
GIÚP MÌNH VỚI!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
số cần tìm là :
\(\frac{1}{2}+\frac{3}{28}+\frac{2}{8}+\frac{4}{77}+\frac{5}{176}\)
= \(\frac{1935}{2128}\)
\(\frac{1}{2}+\frac{2}{8}+\frac{3}{28}+\frac{4}{77}+\frac{5}{176}=\frac{15}{16}\)
Cho dãy phân số :\(\frac{1}{2};\frac{2}{8};\frac{3}{28};\frac{4}{77};\frac{5}{176};...\)
a)Tìm phân số thứ 20 của dãy số.
b)Phân số\(\frac{16}{7708}\)có thuộc dãy số trên không?
c)Tính tổng 10 phân số đầu tiên.
Bài 1:
\(\frac{32}{15}:\left(-1\frac{1}{5}+1\frac{1}{3}\right)\) \(1\frac{13}{15}.0,75-\left(\frac{8}{15}+0.25\right).\frac{24}{47}\)
\(0,2.\frac{15}{36}-\left(\frac{2}{5}+\frac{2}{3}\right):1\frac{1}{5}\) \(5:\left(4\frac{25}{28}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}+\frac{9}{20}\right)\)
Thực hiện phép tính
\(a,(\frac{-5}{28}+1,75+\frac{8}{35}).(-3\frac{9}{20})\) \(b,(6-2\frac{4}{5}).3\frac{1}{8}-1\frac{3}{5}:\frac{1}{4}\)
\(c,(\frac{7-5}{24}+0,75+\frac{7}{12}):(-2\frac{1}{8})\) \(d,8\frac{2}{7}-(3\frac{4}{7}+4\frac{2}{7})\)
\(e,\left(-3,2\right).\frac{-15}{64}+(0,8-2\frac{4}{15}):3\frac{2}{3}\) \(f,1\frac{13}{15}.\left(0,5\right)^2.3+(\frac{8}{15}-1\frac{19}{60}):1\frac{23}{24}\)
\(g,1,4.\frac{15}{49}-(\frac{4}{5}+\frac{2}{3}):2\frac{1}{5}\)
a: \(=\left(-\dfrac{25}{140}+\dfrac{245}{140}+\dfrac{32}{140}\right)\cdot\dfrac{-69}{20}\)
\(=\dfrac{252}{140}\cdot\dfrac{-69}{20}\)
\(=\dfrac{9}{5}\cdot\dfrac{-69}{20}=\dfrac{-621}{100}\)
b: \(=\left(6-2-\dfrac{4}{5}\right)\cdot\dfrac{25}{8}-\dfrac{8}{5}\cdot4\)
\(=\dfrac{16}{5}\cdot\dfrac{25}{8}-\dfrac{32}{5}=\dfrac{18}{5}\)
c: \(=\left(\dfrac{2}{24}+\dfrac{18}{24}+\dfrac{14}{24}\right):\dfrac{-17}{8}\)
\(=\dfrac{34}{24}\cdot\dfrac{-8}{17}=\dfrac{-1}{3}\cdot2=-\dfrac{2}{3}\)
a) \(\frac{14}{21}+1-|\frac{1}{3}-1|\)
b) \(\frac{1}{3}-|\frac{-1}{4}+\frac{5}{6}|-|\frac{-7}{12}|\)
c) \(|\frac{-5}{6}+\frac{1}{2}|-\frac{1}{3}+|\frac{-5}{12}|\)
d) \(\frac{-10}{6}-\frac{4}{-8}|\frac{-3}{4}+\frac{5}{-2}|\)
e) \(|\frac{-5}{2}|-|\frac{-4}{28}+1|-\frac{-3}{14}\)
g) \(\frac{5}{7}-|\frac{-4}{28}+\frac{1}{2}|-|\frac{-3}{14}|\)
Các bạn giúp mik bài này nhé. Càm ơn nhiều
a) \(\frac{14}{21}+1-\left|\frac{1}{3}-1\right|\)
\(=\frac{2}{3}+1-\frac{2}{3}\)
\(=1+\left(\frac{2}{3}-\frac{1}{3}\right)\)
\(=1\)
b) \(\frac{1}{3}-\left|\frac{-1}{4}+\frac{5}{6}\right|-\left|\frac{-7}{12}\right|\)
\(=\frac{1}{3}-\frac{7}{12}-\frac{7}{12}\)
\(=-\frac{5}{6}\)
\(\frac{1}{3}-|\frac{-1}{4}+\frac{5}{6}|-|\frac{-7}{12}|\)
\(=\frac{2}{3}+1-\frac{2}{3}\)
\(=1+(\frac{2}{3}-\frac{2}{3})\)
\(=1\)
\(3\frac{2}{5}+4\frac{3}{7}-\frac{1}{4}+\frac{44}{77}-2\frac{2}{5}-0,75\)
3 / 2 / 5 + 4 / 3 / 7 - 1 / 4 + 44 / 77 - 2 / 2 / 5 - 0,75
= 17 / 5 + 31 / 7 - 1 / 4 + 4 / 7 - 12 / 5 - 3 / 4
= ( 17 / 5 - 12 / 5 ) + ( 31 / 7 - 4 / 7 ) + ( 1 / 4 + 3 / 4 )
= 1 + 9 + 1
= 11
Bài làm
=17/5 + 31/7 - 1/4 +4/7 - 12/5 - 3/10
=( 17/5+12/5)-(31/7+4/7)-3/10
=29/5-5/1-3/10
=29/5-3/10-5/1
=61/10
Mình ko chác đâu nhé!
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
\(a,1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{47}\)
\(b,5:\left(4\frac{3}{4}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}+\frac{9}{20}\right)\)
\(c,6\frac{5}{12}:2\frac{3}{4}+11\frac{1}{4}.\left(\frac{1}{3}-\frac{1}{5}\right)\)
\(d,\left(\frac{3}{5}+0,415-\frac{3}{200}\right).2\frac{2}{3}.0,25\)
\(e,\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
\(g,1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right);\frac{7}{3}\)