Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
B. 1/3 - 1/3 - 3/5 +3/5 + 5/7 - 5/7 + 9/11 - 9/11 -11/13 + 11/ 13 + 7/9 + 13/15
= 0 -0-0-0-0+7/9 +13/15
= 74/45
a) \(\frac{1}{12}+\frac{3}{15}+\frac{11}{12}+\frac{1}{71}-\frac{12}{10}=\left(\frac{1}{12}+\frac{11}{12}\right)+\left(\frac{1}{5}-\frac{1}{5}\right)+\frac{1}{71}\)
\(=\frac{12}{12}+0+\frac{1}{71}=1+\frac{1}{71}=1\frac{1}{71}=\frac{72}{71}\)
b) \(\frac{2}{3}-4\left(\frac{1}{2}+\frac{3}{4}\right)=\frac{2}{3}-4.\frac{5}{4}=\frac{2}{3}-5=\frac{2}{3}-\frac{15}{3}=-\frac{13}{3}\)
c) \(\frac{-4}{13}.\frac{3}{17}+\frac{-12}{13}.\frac{4}{7}+\frac{4}{13}=\frac{4}{13}.\frac{-3}{17}+\frac{4}{13}.\frac{-12}{17}+\frac{4}{13}.1\)
\(=\frac{4}{13}\left(\frac{-3}{17}+\frac{-12}{17}+1\right)=\frac{4}{13}\left(\frac{-15}{17}+\frac{17}{17}\right)=\frac{4}{13}.\frac{2}{17}=\frac{8}{221}\)
d) \(\frac{10^3+2.5+5^3}{55}=\frac{1000+10+125}{55}=\frac{1135}{55}=\frac{227}{11}\)
\(12\frac{3}{11}-\frac{6}{13}+3,25-5\frac{3}{11}+\sqrt{1\frac{9}{16}}\)
\(=\frac{135}{11}-\frac{6}{13}+\frac{13}{4}-\frac{58}{11}+\sqrt{\frac{25}{16}}\)
\(=\frac{135}{11}-\frac{6}{13}+\frac{13}{4}-\frac{58}{11}+\frac{5}{4}\)
\(=\frac{135}{11}-\frac{58}{11}+\frac{13}{4}+\frac{5}{4}-\frac{6}{13}\)
\(=\frac{77}{11}+\frac{18}{4}-\frac{6}{13}\)
\(=7+\frac{9}{2}-\frac{6}{13}\)
\(=\frac{182}{26}+\frac{117}{26}-\frac{12}{26}\)
\(=\frac{287}{26}\)
\(D=\frac{1}{3}-\frac{3}{5}+\frac{5}{7}-\frac{7}{9}+\frac{9}{11}-\frac{11}{13}+\frac{13}{15}+\frac{11}{13}-\frac{9}{11}+\frac{7}{9}-\frac{5}{7}+\frac{3}{5}-\frac{1}{3}\)
\(D=\left(\frac{1}{3}-\frac{1}{3}\right)-\left(\frac{3}{5}-\frac{3}{5}\right)+\left(\frac{5}{7}-\frac{5}{7}\right)-\left(\frac{7}{9}-\frac{7}{9}\right)+\left(\frac{9}{11}-\frac{9}{11}\right)-\left(\frac{11}{13}-\frac{11}{13}\right)+\frac{13}{15}\)
\(D=0+\frac{13}{15}=\frac{13}{15}\)
( -1,25) . 14,7. ( -8 )
= \(\frac{-5}{4}\). \(\frac{147}{10}\)\(.\frac{\left(-8\right)}{1}\)
= \(\frac{\left(-5\right).147.\left(-8\right)}{4.10.1}.\)
= \(\frac{\left[\left(-5\right).\left(-8\right)\right].147}{\left(4.10\right).1}\)
= \(\left[\frac{-5}{4}.\frac{-8}{10}\right].147\)
=147
\(\text{a,}\frac{2}{13}.\frac{-5}{3}+\frac{11}{13}.\frac{-5}{3}=-\frac{5}{3}\left(\frac{2}{13}+\frac{11}{13}\right)\)
\(=\frac{-5}{3}.\frac{13}{13}\)
\(=-\frac{5}{3}\)
\(\text{b,}\left(-\frac{1}{3}\right)^2+\left(-\frac{1}{3}\right)^3.27+\left(\frac{-2017}{2018}\right)^0=\frac{1}{9}-\frac{1}{27}.27+1\)
\(=\frac{1}{9}-1+1\)
\(=\frac{1}{9}\)
\(\text{c,}1,2-\sqrt{\frac{1}{4}}:1\frac{1}{20}+\left|\frac{3}{4}-1,25\right|-\left(\frac{-3}{2}\right)^2=\frac{6}{5}-\frac{1}{2}:\frac{21}{20}+\left|\frac{3}{4}-\frac{5}{4}\right|-\frac{9}{4}\)
\(=\frac{6}{5}-\frac{10}{21}+\frac{1}{2}-\frac{9}{4}\)
\(=\frac{-431}{420}\)
\(=\frac{\left(-11\right).3.13}{39.4.55}=\frac{\left(-1\right).1.1}{1.4.5}=-\frac{1}{20}\)
\(\left(-\frac{11}{39}\right).\frac{3}{4}.\frac{13}{55}\)
\(=\left(-\frac{11}{52}\right).\frac{13}{55}\)
\(=-\frac{1}{20}.\)
Chúc bạn học tốt!