Tính
a)\(\frac{-15}{27}-\frac{8}{18}+3,5-\left(-\frac{2}{7}\right)\)
Giúp tui
tính
a) \(\frac{-15}{27}-\frac{8}{18}+3,5-\left(-\frac{2}{7}\right)\)
a,\(\frac{3}{7}+\left\{\frac{-5}{2}\right\}+\left\{\frac{-3}{5}\right\}\)
b,\(\frac{-8}{18}-\frac{15}{27}\)
c,\(\frac{4}{5}-\left\{\frac{-2}{7}\right\}-\frac{7}{10}\)
d,\(3,5-\left\{\frac{-2}{7}\right\}\)
a. 3/7+(-5/2)+(-3/5)
= 3/7-5/2-3/5
=30/70-175/70-42/70
=-145/70-42/70
=-187/70
b. -8/18-15/27
= -4/9-15/27
= -12/27-15/27
= -27/27
= -1
c. 4/5-(-2/7)-7/10
=4/5+2/7-7/10
=56/70+20/70-49/70
=76/70-49/70
=27/70
d. 3,5-(-2/7)
=7/2-(-2/7)
=7/2+2/7
=49/14+4/14
=53/114
Tính hợp lí:
a) \(\frac{-8}{15}.\left(-30\right).\left(\frac{15}{-8}\right).\frac{9}{10}\)
b) \(2\frac{1}{18}.\frac{23}{24}.\frac{9}{37}.\frac{48}{-15}\)
c) A=\(\frac{-0,8+\frac{4}{7}+\frac{4}{9}}{0,3.\frac{3}{14}-\frac{3}{18}}+\frac{0,23-3,5+\frac{2}{7}}{0,69-10,5+\frac{6}{7}}\)
\(a,\frac{-8}{15}.\left(-30\right).\frac{15}{-8}.\frac{9}{10}\)
\(=-\left(\frac{8}{15}.\frac{15}{8}\right).\left(30.\frac{9}{10}\right)\)
\(=-1.27
=-27\)
\(b,2\frac{1}{18}.\frac{23}{24}.\frac{9}{37}.\frac{48}{-15}\)
\(=\frac{-37.23.9.48}{18.24.37.15}=\frac{23}{15}\)
c, chịu rồi
a/\(\frac{-1}{21}\)+ \(\frac{-1}{28}\)
b/3,5 - \(\left(\frac{-2}{7}\right)\)
c/\(\frac{-8}{18}\)- \(\frac{15}{27}\)
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a, = [-28+ (-21)]/ (21.28)
=-59/ 588
b, = 53/14
c, = 1/9
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
Giúp mình với các bạn, mình đang cần gấp xin các bạn giúp mình nhé
\(\frac{1}{2}.\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right);\left(\frac{-5}{28}+1,75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right);\frac{1}{3}.\frac{5}{7}-\frac{7}{27}.\frac{36}{14};70,5-528:\frac{15}{2}\)
A) \(\frac{1}{2}\cdot\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right)\)
\(=\frac{1}{2}\cdot\frac{1}{2}\)
\(=\frac{1}{4}\)
B) \(\left(\frac{-5}{28}+1.75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)
\(=\left(\frac{-5}{28}+\frac{7}{4}+\frac{8}{35}\right):\frac{-69}{20}\)
\(=\frac{14}{5}:\frac{-69}{20}\)
\(=\frac{-56}{69}\)
Tính
a) \(\left( {\frac{4}{5} - 1} \right):\frac{3}{5} - \frac{2}{3}.0,5\)
b) \(1 - {\left( {\frac{5}{9} - \frac{2}{3}} \right)^2}:\frac{4}{{27}}\)
c)\(\left[ {\left( {\frac{3}{8} - \frac{5}{{12}}} \right).6 + \frac{1}{3}} \right].4\)
d) \(0,8:\left\{ {0,2 - 7.\left[ {\frac{1}{6} + \left( {\frac{5}{{21}} - \frac{5}{{14}}} \right)} \right]} \right\}\)
a)
\(\begin{array}{l}\frac{1}{9} - 0,3.\frac{5}{9} + \frac{1}{3}\\ = \frac{1}{9} - \frac{3}{{10}}.\frac{5}{9} + \frac{1}{3}\\ = \frac{1}{9} - \frac{3}{{2.5}}.\frac{5}{{3.3}} + \frac{1}{3}\\ = \frac{1}{9} - \frac{1}{6} + \frac{1}{3}\\ = \frac{2}{{18}} - \frac{3}{{18}} + \frac{6}{{18}}\\ = \frac{5}{{18}}\end{array}\)
b)
\(\begin{array}{l}{\left( {\frac{{ - 2}}{3}} \right)^2} + \frac{1}{6} - {\left( { - 0,5} \right)^3}\\ = \frac{4}{9} + \frac{1}{6} - \left( {\frac{{ - 1}}{2}} \right)^3\\ = \frac{4}{9} + \frac{1}{6} - \left( {\frac{{ - 1}}{8}} \right)\\ = \frac{4}{9} + \frac{1}{6} + \frac{1}{8}\\ = \frac{{32}}{{72}} + \frac{{12}}{{72}} + \frac{9}{{72}}\\ = \frac{{53}}{{72}}\end{array}\)
Cộng, trừ hữu tỉ
6. Tính:
a) \(\frac{-1}{21}+\frac{-1}{28}\)
b) \(\frac{-8}{18}-\frac{15}{27}\)
c) \(\frac{-5}{12}+0,75\)
d) \(3,5-\left(-\frac{2}{7}\right)\)
Các bạn giúp mình với huhu, mai mình nộp cho cô rùi
a) \(\frac{-1}{21}\)\(+\)\(\frac{-1}{28}\)\(=\)\(\frac{-1}{12}\)
b) \(\frac{-8}{18}\)\(-\)\(\frac{15}{27}\)\(=\)\(-1\)
c) \(\frac{-5}{12}\)\(+\)\(0.75\)\(=\)\(\frac{-5}{12}\)\(+\)\(\frac{3}{4}\)\(=\)\(\frac{1}{3}\)
d) \(3.5\)\(-\)\(\left(\frac{-2}{7}\right)\)\(=\)\(\frac{7}{2}\)\(+\)\(\frac{2}{7}\)\(=\)\(\frac{53}{14}\)
Tính hợp lý:
\(A=1+\frac{-9}{16}.\frac{13}{27}+\frac{9}{16}.\frac{-14}{27}\)
\(B=\frac{7}{18}.\left(\frac{-12}{23}-\frac{4}{15}\right)+\frac{7}{18}.\left(\frac{8}{30}+\frac{35}{23}\right)\)
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