Thực hiện các phép tính sau ( một cách hợp lí ) tung buoc
d) \(\dfrac{-2}{7}\) - (\(\dfrac{3}{11}\) - \(\dfrac{2}{7}\))
e) (2\(\dfrac{3}{7}\) + 1\(\dfrac{4}{7}\)) - \(\dfrac{17}{7}\)
f) \(\dfrac{-2}{3}\) . \(\dfrac{4}{5}\) + \(\dfrac{1}{5}\) : \(\dfrac{9}{11}\)
h) (-6,2 : 2 + 3,7) : 0,2
d: =-2/7-3/11+2/7=-3/11
e: =2+3/7+1+4/7-17/7
=4-17/7=11/7
f: =-2/3*4/5+1/5*11/9
=-8/15+11/45
=-24/45+11/45=-13/45
h: =(-3,1+3,7):0,2=0,6:0,2=3
Bài 1 . Thực hiện phép tính sau :
a. \(\dfrac{-4}{11}\). \(\dfrac{7}{9}\)+\(\dfrac{-4}{11}\) . \(\dfrac{2}{9}\) - \(\dfrac{7}{11}\)
b. \(\dfrac{3}{5}\):\(\dfrac{-7}{10}\)+ 0,5 - \(\left(-\dfrac{9}{14}\right)\)
c. \(\dfrac{3}{5}\)-\(\dfrac{8}{5}\): (5,25+75%)
Bài 2 . Tìm x :
a) x - \(\dfrac{1}{2}\)= \(\dfrac{-1}{10}\) b.\(\dfrac{2}{3}x\) - \(\dfrac{7}{6}\)=\(\dfrac{5}{2}\) c)2,5 - \(\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)\) =\(\dfrac{3}{4}\)
Mik làm Bài 2 nhé ~
Bài 2 :
a) \(x-\dfrac{1}{2}=-\dfrac{1}{10}\)
\(x=-\dfrac{1}{10}+\dfrac{1}{2}\)
\(x=\dfrac{2}{5}\)
b) \(\dfrac{2}{3}x-\dfrac{7}{6}=\dfrac{5}{2}\)
\(\dfrac{2}{3}x=\dfrac{5}{2}+\dfrac{7}{6}\)
\(\dfrac{2}{3}x=\dfrac{11}{3}\)
\(x=\dfrac{11}{3}:\dfrac{2}{3}\)
\(x=\dfrac{11}{3}.\dfrac{3}{2}\)
\(x=\dfrac{11}{2}\)
c) \(2,5-\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)=\dfrac{3}{4}\)
\(\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)=2,5-\dfrac{3}{4}\)
\(\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)=\dfrac{5}{2}-\dfrac{3}{4}\)
\(\dfrac{1}{8}x+\dfrac{1}{2}=\dfrac{7}{4}\)
\(\dfrac{1}{8}x=\dfrac{7}{4}-\dfrac{1}{2}\)
\(\dfrac{1}{8}x=\dfrac{5}{4}\)
\(x=10\)
Bài 1:
a) \(\dfrac{-4}{11}.\dfrac{7}{9}+\dfrac{-4}{11}.\dfrac{2}{9}-\dfrac{7}{11}\)
\(=\dfrac{-4}{11}.\left(\dfrac{7}{9}+\dfrac{2}{9}\right)-\dfrac{7}{11}\)
\(=\dfrac{-4}{11}.1-\dfrac{7}{11}\)
\(=\dfrac{-4}{11}-\dfrac{7}{11}\)
\(=-1\)
b) \(\dfrac{3}{5}:\dfrac{-7}{10}+0,5-\left(\dfrac{-9}{14}\right)\)
\(=\dfrac{-6}{7}+\dfrac{1}{2}+\dfrac{9}{14}\)
\(=\dfrac{2}{7}\)
c) \(\dfrac{3}{5}-\dfrac{8}{5}:\left(5,25+75\%\right)\)
\(=\dfrac{3}{5}-\dfrac{8}{5}:\left(\dfrac{21}{4}+\dfrac{3}{4}\right)\)
\(=\dfrac{3}{5}-\dfrac{8}{5}:6\)
\(=\dfrac{3}{5}-\dfrac{4}{15}\)
\(=\dfrac{1}{3}\)
Bài 2:
a) \(x-\dfrac{1}{2}=\dfrac{-1}{10}\)
\(x=\dfrac{-1}{10}+\dfrac{1}{2}\)
\(x=\dfrac{2}{5}\)
b) \(\dfrac{2}{3}x-\dfrac{7}{6}=\dfrac{5}{2}\)
\(\dfrac{2}{3}x=\dfrac{5}{2}+\dfrac{7}{6}\)
\(\dfrac{2}{3}x=\dfrac{11}{3}\)
\(x=\dfrac{11}{3}:\dfrac{2}{3}\)
\(x=\dfrac{11}{2}\)
c) \(2,5-\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)=\dfrac{3}{4}\)
\(\dfrac{1}{8}x+\dfrac{1}{2}=\dfrac{5}{2}-\dfrac{3}{4}\)
\(\dfrac{1}{8}x+\dfrac{1}{2}=\dfrac{7}{4}\)
\(\dfrac{1}{8}x=\dfrac{7}{4}-\dfrac{1}{2}\)
\(\dfrac{1}{8}x=\dfrac{5}{4}\)
\(x=\dfrac{5}{4}:\dfrac{1}{8}\)
\(x=10\)
Thực hiện phép tính ( tính nhanh nếu có thể )
a, -5/21 + -2/21 + 8/24
b, 4/11 . -2/7 + 4/11 . -4/7 + 4/11 . -1/7
c, \(10\dfrac{5}{9}\) - ( \(3\dfrac{5}{7}\) + \(4\dfrac{5}{9}\) )
d, 1/3 + \(1\dfrac{3}{4}\) - ( \(1\dfrac{3}{4}\) - 80% )
e, \(5\dfrac{3}{5}\) + \(7\dfrac{21}{48}\) : 10/7 - \(5\dfrac{21}{48}\) : 10/7
f, -5/7 . 2/11 - 5/11 . 9/7 + \(2\dfrac{5}{7}\)
g, -3/13 . 6/8 + 7/13 . -3/8 + \(1\dfrac{3}{8}\)
a: =-1/3+1/3=0
b: \(=\dfrac{4}{11}\left(-\dfrac{2}{7}-\dfrac{4}{7}-\dfrac{1}{7}\right)=\dfrac{4}{11}\cdot\left(-1\right)=-\dfrac{4}{11}\)
c: \(=10+\dfrac{5}{9}-3-\dfrac{5}{7}-4-\dfrac{5}{9}=3-\dfrac{5}{7}=\dfrac{16}{7}\)
d: \(=\dfrac{1}{3}+\dfrac{7}{4}-\dfrac{7}{4}+\dfrac{4}{5}=\dfrac{1}{3}+\dfrac{4}{5}=\dfrac{5+12}{15}=\dfrac{17}{15}\)
a: =-1/3+1/3=0
b: =10+59−3−57−4−59=3−57=167=10+59−3−57−4−59=3−57=167
d:
12+3/7-11+3/7 tính bằng cách thuận tiện nhé
1/Thực hiện phép tính:
𝒂) ( \(\dfrac{7}{5}\) − \(\dfrac{8}{7}\) ) + \(3\dfrac{2}{5}\) ∶ 𝟎,𝟔
b) \(\dfrac{11}{6}\) + \(\dfrac{7}{6}\) ∶ \(\dfrac{-5}{4}\)
c) \(\dfrac{7}{4}\) − \(\dfrac{5}{4}\) . \(\dfrac{8}{15}\)
2/ Tìm x biết
b) 𝒙 + 𝟐,𝟓 = \(\dfrac{-8}{3}\)
b) 𝟐𝒙 − 𝟐𝟎% = \(\dfrac{9}{5}\)
𝒄) ( \(\dfrac{5}{4}\) )2 + 𝒙 = \(2\dfrac{3}{4}\)
\(1\)/
\(a\)) \(=\left(\dfrac{7}{5}-\dfrac{8}{7}\right)+\dfrac{17}{5}:0,6\)
\(=\dfrac{9}{35}+\dfrac{17}{3}\)
\(=\dfrac{622}{105}\)
\(b\)) \(=\dfrac{11}{6}+\dfrac{-14}{15}\)
\(=\dfrac{9}{10}\)
\(c\)/ \(=\dfrac{7}{4}-\dfrac{2}{3}\)
\(=\dfrac{13}{12}\)
Thực hiện phép tính:
a) \(\dfrac{8}{13}\) + \(\dfrac{5}{13}\)
b)\(\dfrac{2}{3}\) + \(\dfrac{-2}{5}\) + \(\dfrac{-5}{6}\) - \(\dfrac{13}{10}\)
c) -\(\dfrac{2}{7}\) - (\(\dfrac{5}{11}\) - \(\dfrac{9}{7}\)) + \(\dfrac{5}{11}\)
d) \(\dfrac{-3}{7}\) x \(\dfrac{-1}{9}\) + \(\dfrac{7}{-18}\) x \(\dfrac{-3}{7}\) + \(\dfrac{5}{6}\) x \(\dfrac{-3}{7}\)
e) \(11\dfrac{1}{4}\) - (\(2\dfrac{5}{7}\) + \(5\dfrac{1}{4}\))
f) (\(8\dfrac{5}{11}\) + \(3\dfrac{5}{8}\)) - \(3\dfrac{5}{11}\)
g) -\(\dfrac{1}{4}\) x \(13\dfrac{9}{11}\) - 0,25 x \(6\dfrac{2}{11}\)
h) \(\dfrac{4}{9}\) : (-\(\dfrac{1}{7}\)) + \(6\dfrac{5}{9}\) : (-\(\dfrac{1}{7}\))
Thực hiện các phép tính:
a,\(\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\)
b, \(10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+3:15\%\)
c. \(4\dfrac{3}{4}+\left(-0,37\right)+\dfrac{1}{8}+\left(-1,8\right)+\left(-2,5\right)+3\dfrac{1}{12}\)
a, = (58/9 + 7/11) - (40/9 - 26/11)
= 701/99 - 206/99
= 5
b, = 51/5 - 11/2 . 60/11 + 3 : 3/20
= 51/5 - 30 + 20
= -99/5 + 20
= 1/5
c, = 19/4 + (-0,37) + 1/8 + (-1,8) + (-2,5) + 37/12
= 219/50 + -67/40 + 7/12
= 1973/600
Thực hiện phép tính (hợp lí nếu có thể):
a) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
b) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . (\(\dfrac{11}{-6}\)) . (-20)
c) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . (\(-4\dfrac{1}{2}\))
a) \(=\left(13\dfrac{2}{7}+2\dfrac{5}{7}\right):\left(-\dfrac{8}{9}\right)\)
\(=16:\dfrac{-8}{9}=\dfrac{-8\cdot\left(-2\right)\cdot9}{-8}=-18\)
b)
\(=\left(\dfrac{-6}{11}\cdot\dfrac{11}{-6}\right)\cdot\dfrac{7\cdot10\cdot\left(-2\right)}{10}\)
\(=-14\)
c) \(=\dfrac{-1}{2}\cdot\dfrac{4}{3}\cdot\dfrac{-7}{2}\)
\(=\dfrac{-1\cdot2\cdot2\cdot\left(-7\right)}{2\cdot3\cdot2}=\dfrac{7}{3}\)
Thực hiện phép tính.(tính nhanh nếu có thể)
1/ \(2\dfrac{1}{3}.3\)
2/ \(\left(\dfrac{2}{5}-\dfrac{3}{4}\right)-\dfrac{2}{5}\)
3/ \(\dfrac{-10}{11}.\dfrac{4}{7}+\dfrac{-10}{11}.\dfrac{3}{7}+1\dfrac{10}{11}\)
\(2\dfrac{1}{3}.3=\dfrac{7}{3}.3=7.\\ \left(\dfrac{2}{5}-\dfrac{3}{4}\right)-\dfrac{2}{5}=\dfrac{2}{5}-\dfrac{3}{4}-\dfrac{2}{5}=-\dfrac{3}{4}.\\ \dfrac{-10}{11}.\dfrac{4}{7}+\dfrac{-10}{11}.\dfrac{3}{7}+1\dfrac{10}{11}.\\ =\dfrac{-10}{11}\left(\dfrac{4}{7}+\dfrac{3}{7}-1\right).\\ =\dfrac{-10}{11}.\left(1-1\right)=0.\)
1) 2\(\dfrac{1}{3}\).3=\(\dfrac{7}{3}\).3=7.
2) (2/5 -3/4) -2/5 = 2/5 -3/4 -2/5 = -3/4.
3) \(\dfrac{-10}{11}.\dfrac{4}{7}+\dfrac{-10}{11}.\dfrac{3}{7}+1\dfrac{10}{11}=\dfrac{1}{11}\left(-\dfrac{40}{7}-\dfrac{30}{7}+21\right)=\dfrac{1}{11}.\left(-10+21\right)=1\).
Thực hiện phép tính (hợp lí nếu có thể):
a) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . \(\dfrac{11}{-6}\) . (-20)
b) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . \(-4\dfrac{1}{2}\))
c) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
\(a.\left[-\dfrac{6}{11}.\dfrac{11}{-6}\right].\dfrac{7}{10}.\left(-20\right)=1.7.\left(-2\right)=-14\)
\(b.\dfrac{-1}{2}:\dfrac{3}{4}.\dfrac{-7}{2}=\dfrac{7}{4}:\dfrac{3}{4}=\dfrac{7}{3}\)
\(c.\dfrac{93}{7}:-\dfrac{8}{9}+\dfrac{19}{7}:\dfrac{-8}{9}=\left(\dfrac{93}{7}+\dfrac{19}{7}\right):-\dfrac{8}{9}=\dfrac{-9}{8}.\dfrac{112}{7}=-18\)
