Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{1}{3}\cdot\frac{5}{7}-\frac{7}{27}\cdot\frac{36}{14}\)
=\(\frac{5}{21}\cdot\frac{2}{3}\)
=\(\frac{10}{63}\)
\(27\cdot36+73\cdot99+27\cdot14-49\cdot7\)
\(=27\cdot\left(36+14\right)+73\cdot99-49\cdot7\)
\(=27\cdot50+6884=1350+6884=8234\)
\(\dfrac{5^6}{5^4}+2^3\cdot2^2-1^{2017}\)
\(=5^2+2^5-1\)
=25+32-1
=25+31
=56
a, 1/2 x ( 2/9 + 3/7 - 5/27 )
= 1/2 x ( 41/63 - 5/27 )
= 1/2 x 88/189
= 44/189
b, (-5/8 + 1,75 + 8/35) : (-3 và 9/10)
= (-5/8 + 7/4 + 8/35) : (-39/10)
= (9/8 + 8/35) : (-39/10)
=379/280 : (-39/10)
= -379/1092
c, 1/3 x 5/7 - 5/27 x 36/14
= 5/21 - 10/21
= -5/21
Chúc bạn học tốt !
a) 1/2 x (\(\frac{42}{189}-\frac{81}{189}-\frac{35}{189}\))=1/2 x 88/189 = 44/189
b) ( \(\frac{-5}{8}+\frac{7}{4}+\frac{8}{35}\)) : \(-3\frac{9}{10}\)
= ( \(\frac{-175}{280}+\frac{490}{280}+\frac{64}{280}\)) : \(\frac{-39}{10}\)
=\(\frac{379}{280}\) x \(\frac{-10}{39}\)=\(\frac{-379}{1092}\)
c) \(\frac{5}{21}\)- \(\frac{10}{21}\)= \(\frac{-5}{21}\)
\(\frac{1}{3}\times\frac{5}{7}-\frac{7}{27}\times\frac{36}{14}\)\(=\frac{1\times5}{3\times7}-\frac{7\times36}{27\times14}\)\(=\frac{5}{21}-\frac{252}{378}=\frac{5}{21}-\frac{2}{3}=\frac{5}{21}-\frac{14}{21}\)\(=\frac{5-14}{21}=\frac{-9}{21}=\frac{-3}{7}\)
\(\frac{1}{3}.\frac{5}{7}-\frac{7}{27}.\frac{36}{14}=\frac{5}{21}-\frac{2}{3}=-\frac{9}{21}=-\frac{3}{7}\)
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 - \(\dfrac{7}{5}\)
= - \(\dfrac{7}{5}\)
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 + \(\dfrac{80}{87}\)
= - \(\dfrac{7}{87}\)
1/3.5/7-7/27.36/14
=1/3.5/7-7/27.18/7
=5/21-2/3
=5/21-14/21
=-9/21=-3/7
****
1/3.5/7-7/27.36/14
=1/3.5/7-7/27.18/7
=5/21-2/3
=5/21-14/21
=-9/21=-3/7
1: =-2/9(15/17+2/17)=-2/9
2: \(=\dfrac{-6}{3}+\dfrac{-21}{90}\)
=-2-7/30=-67/30
3: \(=\dfrac{3}{4}\cdot\dfrac{7}{5}+\dfrac{9}{7}\cdot\dfrac{3}{2}\)
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
1: =-2/9(15/17+2/17)=-2/9
2: =−63+−2190=−63+−2190
=-2-7/30=-67/30
3: =34⋅75+97⋅32=34⋅75+97⋅32
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
Giúp mk nha
-3/7
CHÚC ANH/ CHỊ HỌC GIỎI