\(0,2+\dfrac{16}{21}-\dfrac{9}{5}+\dfrac{5}{21}\)
thực hiện phép tính
a)\(\left(\dfrac{9}{25}-2,18\right):\left(3\dfrac{4}{5}+0,2\right)\)
b)\(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}\)
c)\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
d)\(\dfrac{2^{12}.3^5-4^6.81}{2^2.3^6+8^4.3^5}\)
e)\(4\left(-\dfrac{1}{2}\right)^2-2.\left(\dfrac{-1}{2}\right)^2+3.\left(\dfrac{-1}{2}\right)+1\)
g)\(\sqrt{\dfrac{4}{81}}:\sqrt{\dfrac{25}{81}}-1\dfrac{2}{5}\)
Tính
a) \(\left(\dfrac{9}{25}-2,18\right):\left(3\dfrac{4}{5}+0,2\right)\)
b) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,25+\dfrac{16}{21}\)
a)
= -\(\dfrac{45.5}{25}\) : ( \(3\dfrac{4}{5}\)+ 0.2)
= -\(\dfrac{45.5}{25}\) : 4
= -1,82 : 4
= - 0,455
\(a,\dfrac{3}{5}+\dfrac{-5}{9}\)
\(b,\dfrac{1}{3}+\dfrac{-4}{3};\dfrac{4}{7}\)
\(c,-\dfrac{27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}\)
\(a,\dfrac{3}{5}+\dfrac{-5}{9}=\dfrac{27-25}{45}=\dfrac{2}{49}.\)
\(c,\dfrac{-27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}=\dfrac{-23}{23}+\dfrac{21}{21}+\dfrac{1}{2}=-1+1+\dfrac{1}{2}=\dfrac{1}{2}.\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}=\dfrac{-8}{9}+\dfrac{1}{9}.\left(\dfrac{2}{9}+\dfrac{7}{9}\right)=\dfrac{-8}{9}+\dfrac{1}{9}.1=\dfrac{-8+1}{9}=\dfrac{-7}{9}.\)
Thực hiện phép tính:
a) \(\left(\dfrac{9}{25}-2.18\right):\left(3\dfrac{4}{5}+0,2\right)\)
b) \(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}\)
c) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
d) \(\dfrac{21}{47}+\dfrac{9}{45}+\dfrac{26}{47}+\dfrac{4}{5}\)
e) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)
Mình chỉ cho đáp án thôi,sai thì châm chước cho mìn nha!
a)-91 phần200
b)-25phần 4
c)5 phần 2
d)2
e)0
a, ( 0,36-2,18) : ( 3,8 + 0,2)
= -1,82 : 4
=-0,455 hay -91/200
b, 3/8*19/1/3-3/8*33/1/3
=3/8*(19/1/3-33/1/3)
=3/8*(-14)
=-21/4
Thực hiện phép tính hợp lí;
a) \(\left(\dfrac{9}{25}-2,18\right):\left(3\dfrac{4}{5}+0,2\right)\)
b) \(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}\)
c) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
a)Ta có:\(\left(\dfrac{9}{25}-2,18\right):\left(3\dfrac{4}{5}+0,2\right)=-1,82:4=-\dfrac{91}{200}=-0,455\)
b)Ta có:\(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}=\dfrac{3}{8}\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)=\dfrac{3}{8}.\left(-14\right)=-\dfrac{21}{4}=-5,25\)
c)Ta có:\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}=(1\dfrac{4}{23}-\dfrac{4}{23})+\left(\dfrac{5}{21}+\dfrac{16}{21}\right)+0,5=1+1+0,5=2,5\)Chúc bạn học tốt!!
\(\dfrac{4}{9}.19\dfrac{1}{3}+\dfrac{-4}{9}.39\dfrac{1}{3}+\dfrac{-3^2}{5}:\left(-0,2\right)\)
\(\dfrac{\left(-5^3\right)^2}{27}.\dfrac{3}{23}.\dfrac{6^2}{-5^6}\)
\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
\(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}:33\dfrac{1}{3}\)
\(\dfrac{3}{4}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\)
x:(-2,14)=(-3,12):1,2
Tính 1 câu thoy nhé !
\(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)
= \(\dfrac{3}{7}.\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)\)
=\(\dfrac{3}{7}.-14=-6\)
\(\dfrac{-5}{21}+(\dfrac{-16}{21}+1)\)
\(\dfrac{-3}{8}.\dfrac{1}{6}+\dfrac{3}{-8}.\dfrac{5}{6}+\dfrac{-10}{16}\)
a)
\(\dfrac{-5}{21}+\left(\dfrac{-16}{21}+1\right)=\dfrac{-5}{21}+\dfrac{-16}{21}+1\)=\(-1+1=0\)
`(-5)/21+((-16)/21+1)`
`=(-5)/21-16/21+1`
`=-1+1=0`
`(-3)/8*1/6+3/(-8)*5/6+(-1)/16`
`=-3/8*(1/6+5/6)-10/16`
`=-3/8-10/16`
`=-6/16-10/16=-16/16=-1`
\(\dfrac{-3}{8}.\dfrac{1}{6}+\dfrac{-3}{8}.\dfrac{5}{6}+\dfrac{-10}{16}\)
=\(\dfrac{-3}{8}.\left(\dfrac{1}{6}+\dfrac{5}{6}\right)+\dfrac{-10}{16}\)
=\(\dfrac{-3}{8}+\dfrac{-5}{8}=-1\)=
1) \(\dfrac{5}{13}\) +\(\dfrac{-5}{17}\) + \(\dfrac{-20}{41}\) + \(\dfrac{8}{13}\) +\(\dfrac{-21}{41}\)
2) \(\dfrac{1}{5}\) + \(\dfrac{-2}{9}\) + \(\dfrac{-7}{9}\) + \(\dfrac{4}{5}\) +\(\dfrac{16}{17}\)
3) \(\dfrac{2}{3.5}\) + \(\dfrac{2}{5.7}\) +\(\dfrac{2}{7.9}\) +....................+ \(\dfrac{2}{99.101}\)
1: =5/13+8/13-20/41-21/41-5/17
=1-1-5/17=-5/17
2: =1/5+4/5-2/9-7/9+16/17
=16/17+1-1=16/17
3: =1/3-1/5+1/5-1/7+...+1/99-1/101
=1/3-1/101
=98/303
a) \(\dfrac{-21}{15}\).\(\dfrac{-10}{14}\) b)\(\left(-\dfrac{2}{3}\right)^2\) c)\(\dfrac{-3}{4}\).\(\dfrac{-4}{5}\).\(\dfrac{16}{9}\) d)\(\dfrac{-8}{3}\).\(\dfrac{5}{6}\) e)\(\dfrac{16}{30}\).\(\dfrac{5}{12}\) f) \(\dfrac{13}{30}\).\(\dfrac{-1}{5}\) g)\(\dfrac{2}{21}\).\(\dfrac{3}{28}\) h)\(\left(\dfrac{-3}{4}\right)^3\)
`a, -21/15 . (-10)/14 = 210/210=1`
`b, (-2/3)^2= 4/9`
`c, (-3)/4 . (-4)/5 . 16/9= 192/180=16/15`
`d, (-8)/3 . 5/6= -40/18=-20/9`
`e, 16/30 . 5/12= 8/15 . 5/12=40/180=2/9`
`f, 13/30 . (-1)/5= -13/150`
`g, 2/21 . 3/28= 6/588= 1/98`
`h, (-3/4)^3= -27/64`