Tinh bang cach hop li
c)\(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\) \(\frac{-2}{7}+\frac{1}{4}\)
Tinh bang cach hop li
c) \(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}\) \(+\frac{-2}{7}+\frac{1}{4}\)
=(-5/7-2/7)+(3/4+1/4)-1/5=-1+1-1/5=-1/5
(-5/7+-2/7)+(3/4+1/4)+-1/5
-1+1+-1/5
-1/5
c, \(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}\)
\(=\left(-\frac{5}{7}-\frac{2}{7}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{1}{5}\)
\(=-1+1-\frac{1}{5}=-\frac{1}{5}\)
a, \(\frac{\frac{7}{12}+\frac{5}{6}-1}{5-\frac{3}{4}+\frac{1}{3}}\)
\(\frac{\frac{1}{9}-\frac{5}{6}-4}{\frac{7}{12}-\frac{1}{36}-10}\)
\(\frac{\frac{1}{9}-\frac{5}{6}-4}{\frac{7}{12}-\frac{1}{36}-10}=\frac{36.\left(\frac{1}{9}-\frac{5}{6}-4\right)}{36.\left(\frac{7}{12}-\frac{1}{36}-10\right)}\)
\(=\frac{4-6.5-36.4}{3.7-1-36.10}\)
\(=\frac{4-30-144}{21-1-360}\)
\(=\frac{-26-144}{20-360}=\frac{-170}{-340}=\frac{1}{2}\)
\(\frac{\frac{4}{36}-\frac{30}{36}-\frac{144}{36}}{\frac{21}{36}-\frac{1}{36}-\frac{360}{36}}=\frac{\frac{-170}{36}}{\frac{-340}{36}}=\frac{-170}{36}:\frac{-340}{36}=\frac{-170}{36}.\frac{36}{-340}=\frac{-170}{-340}=\frac{1}{2}\)
bai: Thuc hien phep tinh bang cach hop ly nhat:
a) \((\frac{1}{5}-\frac{1}{4})^2\)
b) \((\frac{5}{3}+\frac{1}{2}):\frac{-13}{5}+1\frac{5}{6}\)
c) \((\frac{3}{17})^4.(\frac{-17}{6})^4\)
a, \(\left(\frac{1}{5}-\frac{1}{4}\right)^2=\left(\frac{-1}{20}\right)^2=\frac{1}{400}\)
b, \(\left(\frac{5}{3}+\frac{1}{2}\right):\frac{-13}{5}+1\frac{5}{6}\)
=> \(\frac{13}{6}:\frac{-13}{5}+\frac{11}{6}\)
=> \(\frac{13}{6}.\frac{5}{-13}+\frac{11}{6}\)
=> \(\frac{-5}{6}+\frac{11}{6}=\frac{6}{6}=1\)
c, \(\left(\frac{3}{17}\right)^4.\left(\frac{-17}{6}\right)^4\)
=> \(\left(\frac{3}{17}.\frac{-17}{6}\right)^4=\left(\frac{-1}{2}\right)^4=\frac{1}{16}\)
a) \(\left(\frac{1}{5}-\frac{1}{4}\right)^2=\left(-\frac{1}{20}\right)^2=\frac{1}{400}.\)
b) \(\left(\frac{5}{3}+\frac{1}{2}\right):-\frac{13}{5}+1\frac{5}{6}\)
= \(\frac{13}{6}:\left(-\frac{13}{5}\right)+\frac{11}{6}\)
= \(\left(-\frac{5}{6}\right)+\frac{11}{6}\)
= \(1.\)
c) \(\left(\frac{3}{17}\right)^4.\left(-\frac{17}{6}\right)^4\)
= \(\left[\frac{3}{17}.\left(-\frac{17}{6}\right)\right]^4\)
= \(\left(-\frac{1}{2}\right)^4=\frac{1}{16}.\)
Chúc bạn học tốt!
Tinh bang cach hop li
a) \(\left(\frac{1}{4}+\frac{-5}{13}\right)\)+ \(\left(\frac{2}{11}+\frac{-8}{13}+\frac{3}{4}\right)\)
b)\(\left(\frac{21}{31}+\frac{-16}{7}\right)\)+\(\left(\frac{44}{53}+\frac{10}{31}\right)+\frac{9}{53}\)
a)(1/4+3/4)-(5/13+8/13)+2/11=1-1+2/11=2/11
b)(21/31+10/31)-16/7+(44/53+9/53)=1+1-16/7=14/7-16/7=-2/7
bằng2/11
-16/7
a, \(\left(\frac{1}{4}+\frac{-5}{13}\right)+\left(\frac{2}{11}+\frac{-8}{13}+\frac{3}{4}\right)\)
\(=\left(\frac{1}{4}-\frac{5}{13}\right)+\left(\frac{2}{11}-\frac{8}{13}+\frac{3}{4}\right)\)
\(=\frac{1}{4}-\frac{5}{13}+\frac{2}{11}-\frac{8}{13}+\frac{3}{4}=1-1+\frac{2}{11}=\frac{2}{11}\)( vì \(\left(\frac{1}{4}+\frac{3}{4}\right)+\left(-\frac{5}{13}-\frac{8}{13}+\frac{2}{11}\right)\))
b, \(\left(\frac{21}{31}+\frac{-16}{7}\right)+\left(\frac{44}{53}+\frac{10}{31}\right)+\frac{9}{53}\)
\(=\frac{21}{31}-\frac{16}{7}+\frac{44}{53}+\frac{10}{31}+\frac{9}{53}\)
\(=1-\frac{16}{7}+1=\frac{7}{7}-\frac{16}{7}+\frac{7}{7}=-\frac{2}{7}\)
tinh hop li :
\(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)
Tinh bang cach hop li
\(\frac{-3}{31}+\frac{-6}{17}+\frac{1}{25}+\)\(\frac{-28}{31}+\frac{-11}{17}+\frac{-1}{5}\)
âm 2( số -2) và 4/25
\(\frac{-3}{31}+\frac{-6}{17}+\frac{1}{25}+\frac{-28}{31}+\frac{-11}{17}+\frac{-1}{5}\)
\(=\left(\frac{-3}{31}+\frac{-28}{31}\right)+\left(\frac{-6}{17}+\frac{-11}{17}\right)+\left(\frac{1}{25}+\frac{-1}{5}\right)\)
\(=\frac{-31}{31}+\frac{-17}{17}+\frac{-4}{25}\)
\(=\left(-1\right)+\left(-1\right)+\frac{-4}{25}\)
\(=\frac{\left(-25\right)+\left(-25\right)+\left(-4\right)}{25}\)
\(=\frac{-54}{25}\)
(-3/31+-28/31)+(6/17+11/17)+1/25+-1/5
-1+-1+1/25 +-1/5
-2+1/25+-1/5
-2/1+1/25+-1/5
-50/25+1/25+-5/25
-49/25+-5/25
-54/25
mik đúng mn k cho mik nha cảm ơn mn
Tinh bang cach hop ly
\(\frac{-3}{31}+\frac{-6}{17}+\frac{1}{25}+\) \(\frac{-28}{31}+\frac{-11}{17}+\frac{-1}{5}\)
Tinh bang cach gop li
\(\frac{1}{2}\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right)\)
1/2 . ( 2/9 + 3/7 - 5/27 )
=1/2 . ( 2/9-5/27)+3/7
=1/2 . (1/27+3/7)
=1/2 .
\(\frac{1}{2}\times\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{21}\right)\)
\(=\frac{1}{2}\times\frac{88}{189}\)
\(=\frac{44}{189}\)
Học Tốt