Tính :
a) 1,(3) + 0,(23)
b) 12,0(3) - 11,(2)
Những câu hỏi liên quan
Bài tập về nhà
Bài 1: Thực hiện phép tính
a)
3 3 121 3 :4 8 6
− −
b) 7 8 45
23 6 18
− − c) 1 5 0, 75 :4 6
− −
d) 5 5 3 1 11:4 4 8 6 12
− − + e) 4 7 1, 25 5 3 11
− − f)4 4 0,84 0, 64 9 13
7 7 0, 2 0, 559 13
− + +
+ −
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Nhanh giúp mình nha
ko xem dc de ban oi :/
Tính nhanh:
a) 2.dfrac{3}{7}+left(dfrac{2}{9}-1dfrac{3}{7}right)-dfrac{5}{3}:dfrac{1}{9}
b) dfrac{-11}{23}.dfrac{6}{7}+dfrac{8}{7}.dfrac{-11}{23}-dfrac{1}{23}
c) left(dfrac{377}{-231}-dfrac{123}{89}+dfrac{34}{791}right).left(dfrac{1}{6}-dfrac{1}{8}-dfrac{1}{24}right)
d) 19dfrac{5}{8}:dfrac{7}{12}-15dfrac{1}{4}:dfrac{7}{12}
e) dfrac{2}{5}.dfrac{1}{3}-dfrac{2}{15}:dfrac{1}{5}+dfrac{3}{5}.dfrac{1}{3}
Đọc tiếp
Tính nhanh:
a) \(2.\dfrac{3}{7}+\left(\dfrac{2}{9}-1\dfrac{3}{7}\right)-\dfrac{5}{3}:\dfrac{1}{9}\)
b) \(\dfrac{-11}{23}.\dfrac{6}{7}+\dfrac{8}{7}.\dfrac{-11}{23}-\dfrac{1}{23}\)
c) \(\left(\dfrac{377}{-231}-\dfrac{123}{89}+\dfrac{34}{791}\right).\left(\dfrac{1}{6}-\dfrac{1}{8}-\dfrac{1}{24}\right)\)
d) \(19\dfrac{5}{8}:\dfrac{7}{12}-15\dfrac{1}{4}:\dfrac{7}{12}\)
e) \(\dfrac{2}{5}.\dfrac{1}{3}-\dfrac{2}{15}:\dfrac{1}{5}+\dfrac{3}{5}.\dfrac{1}{3}\)
Bài 1: Tính a) -7/9 . 2/3/4 (2/3/4 là hỗn số : 2 là số nguyên, 3/4 là phân số)b) 2/3 + 1/3 . (-2/5)c) 3/4 . 15/1/3 - 3/4 . 43/1/3d) (-49,1) . 13/27 - 58,9 . 13/27e) 0,375 : (-4,5)f) 3/1/7 : (-1/3/7)g) 9/1/3 : 4/2/3 - 2h) (7/3/4 : 0,3125 + 4,5 . 2/2/45) : (-8,5)Bài 2: Tính giá trị biểu thứcA (-6/11) . 7/10 . (11/-6).(-20)B (-1/9) . (-17/29) . 58/51C (-3/7) . 5/11 + (-5/14) . 5/11D (1/1/27 . 12/23 . 9/14) : (-3/23)Bài 3: Tìm xa) 3/7 . x - 2/5 . x -17/35b) (3/4 . x -9/16) . [1/3 + (-3/5) :...
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Bài 1: Tính
a) -7/9 . 2/3/4 (2/3/4 là hỗn số : 2 là số nguyên, 3/4 là phân số)
b) 2/3 + 1/3 . (-2/5)
c) 3/4 . 15/1/3 - 3/4 . 43/1/3
d) (-49,1) . 13/27 - 58,9 . 13/27
e) 0,375 : (-4,5)
f) 3/1/7 : (-1/3/7)
g) 9/1/3 : 4/2/3 - 2
h) (7/3/4 : 0,3125 + 4,5 . 2/2/45) : (-8,5)
Bài 2: Tính giá trị biểu thức
A = (-6/11) . 7/10 . (11/-6).(-20)
B = (-1/9) . (-17/29) . 58/51
C = (-3/7) . 5/11 + (-5/14) . 5/11
D = (1/1/27 . 12/23 . 9/14) : (-3/23)
Bài 3: Tìm x
a) 3/7 . x - 2/5 . x = -17/35
b) (3/4 . x -9/16) . [1/3 + (-3/5) : x] = 0
c) (x + 3/5) . (x + 1) = 0
1.
a) \(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)
b) \(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{8}{15}\)
c) \(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}=\frac{23}{2}-\frac{65}{2}=-21\)
d) \(\left(-49,1\right).\frac{13}{27}-58,9.\frac{13}{27}=\frac{13}{27}.\left(-49,1-58,9\right)=\frac{13}{27}.\left(-108\right)=-52\)
e) \(0,375:\left(-4,5\right)=\frac{-1}{12}\)
f) \(3\frac{1}{7}:\left(-1\frac{3}{7}\right)=\frac{22}{7}:\frac{-10}{7}=\frac{-11}{5}\)
g) \(9\frac{1}{3}:4\frac{2}{3}-2=\frac{28}{3}:\frac{14}{3}-2=2-2=0\)
h) \(\left(7\frac{3}{4}:0,3125+4,5.2\frac{2}{45}\right):\left(-8,5\right)=\left(\frac{31}{4}:\frac{5}{16}+\frac{9}{2}.\frac{92}{45}\right):\frac{-17}{2}=\left(\frac{124}{5}+\frac{46}{5}\right):\frac{-17}{2}=34:\frac{-17}{2}=-4\)
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Bài 1 : Tính:
a)
\(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)
b)
\(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{10}{15}+\frac{-2}{15}=\frac{8}{15}\)
c)
\(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}\)\(=\frac{23}{2}-\frac{65}{2}=\frac{-42}{2}=-21\)
....
Tự lm tiếp dạng như v
Bài 2 :
\(A=\frac{-6}{11}.\frac{7}{10}.\frac{11}{-6}.-20=\left(\frac{-6}{11}.\frac{11}{-6}\right).\left(\frac{7}{10}.-20\right)\)\(=1.\left(-14\right)=-14\)
.....
Bài 3 :
\(\frac{3}{7}.x-\frac{2}{5}.x=\frac{-17}{35}\)
\(\Leftrightarrow\frac{3}{7}-\frac{2}{5}.x=\frac{-17}{35}\)
\(\Leftrightarrow\frac{1}{35}x=\frac{-17}{35}\)
\(\Leftrightarrow x=\frac{-17}{35}:\frac{1}{35}\)
\(\Leftrightarrow x=\frac{-17}{35}.35=-17\)
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Câu 1 : thực hiện phép tính ( tính hợp lí nếu có thể ) A, 3/5 + -4/9 B, 3/5 + 2/5 . 15/8 C, 7/2 . 8/13 + 8/13 . -5/2 + 8/13 D, -5/17 . -9/23 + 9/23 . -22/17 + 11 9/23 Lưu ý : 11 9/23 là hỗn số
`a)3/5+(-4/9)`
`=3/5-4/9`
`=27/45-20/45`
`=7/45`
`b)3/5+2/5 . 15/8`
`=3/5 + 30/40`
`=3/5+3/4`
`=12/20+15/20`
`=27/20`
`c)7/2 . 8/13 + 8/13 . (-5/2)`
`=8/13 . (7/2 +(-5)/2)`
`=8/13 . 1`
`=8/13`
`d)-5/17 . (-9/23)+9/23 . (-22/17) + 11 9/23`
`=-5/17 . (-9/23) + 9/23 . (-1) . 22/17 + 11 + 9/23`
`=-5/17 . (-9/23) + (-9/23) . 22/17+11+9/23`
`= -9/23 ( -5/17 + 22/17)+11+9/23`
`= - 9/23 . 1+11+9/23`
`=-9/23+11+9/23`
`=(-9/23+9/23)+11`
`=0+11`
`=11`
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a: =27/45-20/45=7/45
b: =3/5+30/40
=3/5+3/4
=12/20+15/20
=27/20
c: =8/13(7/2-5/2+1)=8/13*2=16/13
d: =9/23*5/17-9/23*22/17+11+9/23
=-9/23+11+9/23
=11
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Tính nhanh ( Giúp mình nha )
a) -3/7 + 15/26 - ( 2/13 - 3/7 )
b) 2.3/7 + (2/9 -1 3?7 ) -5/3 :1/9
c) -11/23* 6/7 +8/7 * -11/23 - 1/23
d)(377/-231-123/89+ 34/791) * (1/6 -1/8-1/24)
- Kasamita :)))
Tính
a) 4/3*7 + 4/7*11 + 4/11*15 + 4/15*19 + 4/19*23 + 4/23*27
b) 1/2*3 + 1/3*4 + 1/4*5 + 1/5*6 +1/6*7
c) 2/3*5 + 2/5*7 + 2/7*9 + 2/9*11 + 2/11*13 + 2/1*2 + 2/2*3 + 2/3*4 + 2/8*9 + 2/9*10
a)\(\frac{4}{3.7}+\frac{4}{7.11}+...+\frac{4}{23.27}=\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+...+\frac{1}{23}-\frac{1}{27}=\frac{1}{3}-\frac{1}{27}=\frac{8}{27}\)
b)\(\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{6.7}=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{6}-\frac{1}{7}=\frac{1}{2}-\frac{1}{7}=\frac{5}{14}\)
c)\(\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{11.13}+\frac{2}{1.2}+\frac{2}{2.3}+...+\frac{2}{9.10}=\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{11}-\frac{1}{13}\right)+2\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{9}-\frac{1}{10}\right)\)
\(=\frac{1}{3}-\frac{1}{13}+2\left(1-\frac{1}{10}\right)=\frac{10}{39}+\frac{9}{5}=\frac{401}{195}\)
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1. tính hợp lí
a, (25/49 x 17/39+22/39x25/49)x41/25 b, 3+3/11+3/23/8+8/11+8/23:9/8-1/3 c, A=2/3x7+2/7x11+2/11x15+......+2/107x111
a)\(\left(\frac{25}{49}+\frac{17}{39}+\frac{22}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)
\(=\left(\frac{25}{49}+\left(\frac{17}{39}+\frac{22}{39}\right)\times\frac{25}{49}\right)\times\frac{41}{25}\)
\(=\left(\frac{25}{49}+\frac{39}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)
\(=\left(\frac{25}{49}+1\times\frac{25}{49}\right)\times\frac{41}{25}\)
\(=\left(\frac{25}{49}+\frac{25}{49}\right)\times\frac{41}{25}\)
\(=\frac{50}{49}\times\frac{41}{25}\)
\(=\frac{2050}{1225}\)
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Ai giúp gấp đi ạ !
Tính nhanh
A) B =3/2×5+3/5×8+3/8×11+3/11×14
B)3/1×2+3/2×3+3/3×4+...+3/99×100
C)4 /3×7+4/7×11+4/11×15+4/15×19+4/19×23+4/23×27
D) (1-1/3)×(1-1/4)×(1-1/5)×(1-1/6)×...×(1-1/99)
a) \(B=\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}\)
\(=\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}-\frac{1}{8}+\frac{1}{11}+\frac{1}{11}-\frac{1}{14}\)
\(=\frac{1}{2}-\frac{1}{14}=\frac{3}{7}\)
b) Ta có : A = \(\frac{3}{1.2}+\frac{3}{2.3}+\frac{3}{3.4}+...+\frac{3}{99.100}\)
\(=3.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}\right)\)
\(=3.\left(1-\frac{1}{100}\right)\)
\(=3.\frac{99}{100}=\frac{297}{100}\)
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Bài 4 : Tính giá trị các biểu thức :
a. A= 22 - (-32)3 + 4-2 .16-2.52 .
b. B= (23 : 1/2) . 1/2+3-2.9-7. (14/25)0+5 .
c. C= 2-3 + (52)3.5-3+4-3 . 16 -2.32-105. (24/51)0 .
d. D= (2-3.1/2-2).2/3+4-2.8-7.(17/23)0+19 .
A=\(2^2-9^3+4^{-2}.16-2.5^2\)
\(=4-729+1-50=-774\)
B=\(\left(2^3.2\right).\dfrac{1}{2}+3^{-2}.3^2-7.1+5\)
\(B=2^4.\dfrac{1}{2}+1-7+5=8+1-7+5=7\)
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C = 2-3 + (52)3.5-3 + 4-3.16 - 2.32 - 105.(\(\dfrac{24}{51}\))0
C = \(\dfrac{1}{8}\) + 56.5-3 + 4-3.42 - 2.9 - 105.1
C = \(\dfrac{1}{8}\) + 53 + \(\dfrac{1}{4}\) - 18 - 105
C = (\(\dfrac{1}{8}\) + \(\dfrac{1}{4}\)) - (105 - 125 + 18)
C = \(\dfrac{3}{8}\) - (-20 + 18)
C = \(\dfrac{3}{8}\) + 2
C = \(\dfrac{19}{8}\)
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D = 2-3 . \(\dfrac{1}{2^{-2}}\).\(\dfrac{2}{3}\) + 4-2.8 - 7. (\(\dfrac{17}{23}\))0 + 19
D = 2-1.\(\dfrac{2}{3}\) + \(\dfrac{1}{16}\).8 - 7.1 + 19
D = \(\dfrac{1}{3}\) + \(\dfrac{1}{2}\) - 7 + 19
D = \(\dfrac{5}{6}\) + (19 - 7)
D = \(\dfrac{5}{6}\) + 12
D = \(\dfrac{77}{6}\)
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