\(\frac{35}{34}\)+ \(\frac{7}{21}\)+ \(\frac{19}{54}\)+\(\frac{20}{15}\)+\(\frac{2016}{2017}\)
\(\frac{35}{34}\)+ \(\frac{7}{21}\)+ \(\frac{19}{54}\)\(-\)\(\frac{20}{15}\)\(+\)\(\frac{2016}{2017}\)
\(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{1}{6}\)
Giúp mình với mình bị trừ điểm hỏi đáp rồi
\(\frac{15}{31}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{1}{6}\)
\(=\frac{15}{31}+\frac{1}{3}+\frac{19}{34}-\frac{20}{15}+\frac{1}{6}\)
\(=\frac{76}{93}+\frac{19}{34}-\frac{20}{15}+\frac{1}{6}\)
\(=1,37602783-\frac{20}{15}+\frac{1}{6}\)
\(=1,37602783-\frac{4}{3}+\frac{1}{6}\)
\(=0,04269449667+\frac{1}{6}\)
\(=0,2093611633\)
Câu 1. Tính hợp lý giá trị các biểu thức sau :
a. A = ( 689 - 31 ) - ( 269 - 131 )
b. B = \(\left(\frac{1}{2}+\frac{2016}{2017}+\frac{2017}{2018}+1\right)\times\left(\frac{2016}{2017}+\frac{2017}{2018}+\frac{3}{4}\right)-\left(\frac{1}{2}+\frac{2016}{2017}+\frac{2017}{2018}\right)\times\left(\frac{2016}{2017}+\frac{2017}{2018}+\frac{3}{4}+1\right)\)c. C = \(1-\frac{5}{6}+\frac{7}{12}-\frac{9}{20}+\frac{11}{30}-\frac{13}{42}+\frac{15}{56}-\frac{17}{72}+\frac{19}{90}\)
C\(\frac{1}{1}-\frac{1}{2.3}+\frac{1}{3.4}-\frac{1}{4.5}+\frac{1}{5.6}\)-\(\frac{1}{6.7}\)+\(\frac{1}{7.8}\)-\(\frac{1}{8.9}+\frac{1}{9.10}\)
c=\(\frac{1}{1}-\frac{1}{10}\)
c=\(\frac{9}{10}\)
còn a và b rễ lắm mình ko thích làm bài rễ đâu bạn cố chờ lời giải khác nhé!
TÍNH :
\(A=\frac{\frac{5}{18}+\frac{6}{19}+\frac{7}{20}+\frac{8}{21}+....+\frac{21}{34}-17}{\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+....+\frac{1}{33.34}}\)
cho các phhan số:\(\frac{-21}{27};\frac{-14}{19};\frac{-42}{-54};\frac{35}{-45};\frac{-5}{7};\frac{-28}{36}.\) những phân số nào biểu diễn số hữu tỉ \(\frac{-7}{9}?\)
\(-\frac{21}{27};-\frac{35}{45};-\frac{28}{36}\)
a.\(74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}+2\frac{14}{90}\)
b,\(\left(\frac{-2}{5}+\frac{3}{7}\right)-\left(\frac{4}{9}+\frac{12}{20}-\frac{13}{35}\right)+\frac{7}{35}\)
AI GIAI DUOC MINH CHO 20 TICK
a) \(74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}+2\frac{14}{90}\)
= \(\left(74\frac{19}{35}+15\frac{16}{35}\right).\frac{7}{90}+2\frac{14}{90}\)
= 90 . 7/90 + 194/90
= 630/90 + 194/90
= 824/90 = 412/45
b) (-2/5 + 3/7) - (4/9 + 12/20 - 13/35) + 7/35
= -2/5 + 3/7 - 4/9 - 3/5 + 13/35 + 7/35
= (-2/5 - 3/5) + 3/7 - 4/9 + (13/35 + 7/35)
= -1 + 3/7 - 4/9 + 4/7
= -1 + (3/7 + 4/7) - 4/9
= -1 + 1 - 4/9 = -4/9
Bài 1: Thực hiện phép tính a) \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{7}{21}+2\)
Bài 1 :
\(a,\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{7}{21}+2\)
\(=\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{7}{21}-1\frac{7}{21}\right)+2\)
\(=1-1+2\)
\(=2\)
Học tốt
Bài 1 :
a, 15/34+7/21+19/34-1 7/21+2
= 15/34+1/3+19/34-4/3+2
= (15/34+19/34)+(1/3-4/3)+2
= 1+(-1)+2=0+2=2
a,\(\frac{15}{34}\)+\(\frac{7}{21}\)+\(\frac{19}{34}\)-\(\frac{36}{21}\)+\(\frac{2}{3}\)
Ta có: \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{36}{21}+\frac{2}{3}\)
\(=\frac{15}{34}+\frac{19}{34}+\frac{7}{21}-\frac{36}{21}+\frac{2}{3}\)
\(=1-\frac{29}{31}+\frac{2}{3}=\frac{2}{31}+\frac{2}{3}=\frac{68}{93}\)
Câu 1: Thực hiện phép tính bằng cách hợp lí
\(\frac{15}{35}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\)
\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
\(16\frac{2}{7}:\left(-\frac{3}{5}\right)+28\frac{2}{7}:\left(-\frac{3}{5}\right)\)
Câu 2: Tìm x biết
\(2.x-\frac{5}{4}=\frac{20}{15}\)
\(1,5:0,3=x:-15\)
\(|2x-1|=2\)
Câu 3: Thực hiện phép tính hợp lí
\(\frac{11}{12}.\frac{15}{33}+\frac{11}{12}.\frac{2}{22}\)
\(3/3\frac{1}{8}.11\frac{17}{19}-3\frac{1}{8}.13\frac{17}{19}\)
\(28\frac{2}{7}:\left(-\frac{3}{5}\right)+16\frac{2}{7}:\left(-\frac{3}{5}\right)\)