Tính
\(\dfrac{ }{ }\)a, -4/7-5/13.-39/25+-1/42:(-5/6)
b, 2/9.[-4/45:(1/5-2/15)+1 2/3]-5/27
a \(\dfrac{-4}{7}\) - \(\dfrac{5}{13}\) x \(\dfrac{-39}{25}\) + \(\dfrac{-1}{42}\) : \(\dfrac{-5}{6}\)
b \(\dfrac{2}{9}\) x [\(\dfrac{4}{45}\): ( \(\dfrac{1}{5}\) - \(\dfrac{2}{15}\)) + 1\(\dfrac{2}{3}\)] - \(\dfrac{-5}{27}\)
\(a.\dfrac{-4}{7}-\dfrac{5}{13}\times\dfrac{-39}{25}+\dfrac{-1}{42}:\dfrac{-5}{6}\)
\(=\dfrac{-4}{7}+\dfrac{3}{5}+\dfrac{1}{35}\) \(=\dfrac{1}{35}+\dfrac{1}{35}=\dfrac{2}{35}\)
\(b.\dfrac{2}{9}\times\left[\dfrac{4}{5}:\left(\dfrac{1}{5}-\dfrac{2}{15}\right)+1\dfrac{2}{3}\right]-\dfrac{-5}{27}\)
\(=\dfrac{2}{9}\times\left[\dfrac{4}{5}:\dfrac{1}{15}+\dfrac{5}{3}\right]-\dfrac{-5}{27}\)
\(=\dfrac{2}{9}\times\left(12+\dfrac{5}{3}\right)-\dfrac{-5}{27}\)
\(=\dfrac{2}{9}\times\dfrac{41}{3}-\dfrac{-5}{27}=\dfrac{82}{27}-\dfrac{-5}{27}=\dfrac{29}{9}\)
bài 1
4/7+4
3+6/11
3-5/7
21/9-2
15/24+2
63/45-20/25
3/4-2/8
6/7-5/8
37/45-5/9
46/39-11/13
5/12+3/4+1/3
1/2+3/7+11/14
7/10-(1/5+1/4)
15/4-2/3-3/4
`4/7+4`
`=4/7+4/1`
`=4/7+28/7`
`=32/7`
__
`3+6/11`
`=33/11+6/11`
`=39/11`
__
`3-5/7`
`=3/1-5/7`
`=21/7-5/7`
`=16/7`
__
`21/9-2`
`=21/9-18/9`
`=3/9`
`=1/3`
__
`15/24+2`
`=15/24+48/24`
`=63/24`
`=21/16`
__
`63/45-20/25`
`=63/45-4/5`
`=63/45-36/45`
`=27/45`
`=9/15`
__
`3/4-2/8`
`=3/4-1/4`
`=2/4`
__
`6/7-5/8`
`=48/56-35/56`
`=13/56`
__
`37/45-5/9`
`=37/45-25/45`
`=12/45`
`=4/15`
__
`46/39-11/13`
`=46/39-33/39`
`=13/39`
`=1/2`
__
`5/12+3/4+1/3`
`=5/12+9/12+4/12`
`=14/12+4/12`
`=18/12`
`=3/2`
__
`1/2+3/7+11/14`
`=7/14+6/14+11/14`
`=13/14+11/14`
`=24/14`
`=12/7`
__
`7/10-(1/5+1/4)`
`=7/10-(4/20+5/20)`
`=7/10-9/20`
`=14/20-9/20`
`=5/20`
`=1/4`
__
`15/4-2/3-3/4`
`=(15/4-3/4)-2/3`
`=12/4-2/3`
`=3-2/3`
`=9/3-2/3`
`=7/3`
2 ^ 15 : 2 ^ 13 + 3 ^ 2. 2 ^ 3 - 5 ^ 2 - 2 ^ 0
81 . ( 27 + 9 ^ 15) : (3 ^ 5 + 3 ^ 32)
(4 ^ 42 .123 - 23 . 4 ^ 42) : (4 ^ 15 . 4 ^ 27)
(15 . 3 ^ 7 - 3 ^ 8) : (4 . 9 ^ 4)
(100 . 5 ^ 7 + 5 ^ 11 : 25 ) : ( 5 . 5 ^ 13 : 25 ^ 2)
( 2 ^ 5 . 3 ^ 6 . 5 ^ 7 + 2 ^ 6 . 3 ^ 7 . 5 ^ 8 ) : ( 2 ^ 4 . 3 ^ 5 . 5 ^ 6)
(4 ^ 5 . 10 . 5 ^ 6 + 2 ^ 8 . 25 ^ 5) : ( 2 ^ 8 . 5 ^ 4 + 5 ^ 4 + 5 ^ 7 . 2 ^ 5)
tặng 2 like cho người giải !!!
a) 21/47 + 9/45 +26/47 + 4/5
= (21/47 + 26/47) + (9/45 + 4/5)
=1+1 = 2
b) 15/12 + 5/13 - 3/12 - 18/13
= (15/12 - 3/12) + (18/13 - 5/13)
=1+1 = 2
c) 13/25 + 6/41 - 38/25 + 35/41 - 1/2
= (38/25 - 13/25) + (35/41 + 6/41) + 1/2
= 1+1 + 1/2 = 5/2
d) 27/23 + 5/21 - 4/23 + 6/21 + 1/2
= (27/23 - 4/23) + (6/21 - 5/21) + 1/2
= ..........................
Đúng không? Phần sau mình tính sao ra kết quả lạ lắm, tính giúp mình.
(-3/4+2/3):5/11+(-1/4+1/3):5/11
a)|x-13|-35-45=-47
b)(4+x).(x+3)=0
c)25-(5-x)=120-(28-5)
-12/18 + (-21)/35
-3/21 + 6/42
-18/24 + 15/21
1/6 + 2/5
3/5 + (-7)/4
(-2) + (-5)/8
1/-8 + (-5)/9
4/13 + 12/39
1/21 + 1/28
-3/29 + 16/58
8/40 + (-36)/45
-8/18 + (-15)/27
13/30 + (-1)/5
2/21 + 1/28
5 + (-3)/4
18/24 + 45/-10
câu 1)
\(\dfrac{-12}{18}+\left(\dfrac{-21}{35}\right)=\dfrac{-19}{15}\)
câu 2)
\(-\dfrac{3}{21}+\dfrac{6}{42}=0\)
câu 3)
\(-\dfrac{18}{24}+\dfrac{15}{21}=-\dfrac{1}{28}\)
câu 4)
\(\dfrac{1}{6}+\dfrac{2}{5}=\dfrac{17}{30}\)
câu 5)
\(\dfrac{3}{5}+\left(-\dfrac{7}{4}\right)=-\dfrac{23}{20}\)
câu 6)
\(\left(-2\right)+\left(\dfrac{-5}{8}\right)=\dfrac{-21}{8}\)
câu 7)
\(\dfrac{1}{-8}+\left(-\dfrac{5}{9}\right)=-\dfrac{49}{72}\)
câu 8)
\(\dfrac{4}{13}+\dfrac{12}{39}=\dfrac{8}{13}\)
câu 9)
\(\dfrac{1}{21}+\dfrac{1}{28}=\dfrac{1}{12}\)
câu 10)
\(-\dfrac{3}{29}+\dfrac{16}{58}=\dfrac{5}{29}\)
câu 11)
\(\dfrac{8}{40}+\left(-\dfrac{36}{45}\right)=-\dfrac{3}{5}\)
câu 12)
\(-\dfrac{8}{18}+\left(-\dfrac{15}{27}\right)=-1\)
câu 13)
\(\dfrac{13}{30}+\left(-\dfrac{1}{5}\right)=\dfrac{7}{30}\)
câu 14)
\(\dfrac{2}{21}+\dfrac{1}{28}=\dfrac{11}{84}\)
câu 15)
\(5+\left(-\dfrac{3}{4}\right)=\dfrac{17}{4}\)
câu 16)
\(\dfrac{18}{24}+\dfrac{45}{-10}=-\dfrac{15}{4}\)
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
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: =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
a) \(\frac{-4}{7}\)-\(\frac{5}{13}\). \(\frac{-39}{25}\)+\(\frac{-1}{42}\):\(\frac{-5}{6}\)
b) \(\frac{2}{9}.\left[\frac{-4}{45}:\left(\frac{1}{5}-\frac{2}{15}\right)+1\frac{2}{3}\right]-\frac{-5}{27}\)
a) \(-\frac{4}{7}+\frac{\left(-5\right).\left(-39\right)}{13.25}+\frac{\left(-1\right).6}{42.\left(-5\right)}=-\frac{4}{7}+\frac{\left(-1\right).3}{1.5}+\frac{\left(-1\right).1}{7.\left(-5\right)}=-\frac{4}{7}+\frac{3}{5}+\frac{1}{35}\)
\(=-\frac{20}{35}+\frac{21}{35}+\frac{1}{35}=\frac{2}{35}\)
b) \(=\frac{2}{9}.\left[-\frac{4}{45}:\left(\frac{3}{15}-\frac{2}{15}\right)+1\frac{2}{3}\right]+\frac{5}{27}=\frac{2}{9}.\left[-\frac{4}{45}:\frac{1}{15}+1\frac{2}{3}\right]+\frac{5}{27}\)
\(=\frac{2}{9}.\left[\frac{\left(-4\right).15}{45.1}+1\frac{2}{3}\right]+\frac{5}{27}==\frac{2}{9}.\left[\frac{\left(-4\right).1}{3.1}+1\frac{2}{3}\right]+\frac{5}{27}\)
\(==\frac{2}{9}.\left[-\frac{4}{3}+\frac{5}{3}\right]+\frac{5}{27}=\frac{2.1}{9.3}+\frac{5}{27}=\frac{2}{27}+\frac{5}{27}=\frac{7}{27}\)
Tính:
a) \(\dfrac{3^6.45^4-15^{13}.5^{\cdot-9}}{27^4.25^3+45^6}\)
b) \(\dfrac{\left(\dfrac{2}{5}\right)^7.5^7+\left(\dfrac{9}{4}\right)^3:\left(\dfrac{3}{16}\right)^3}{2^7.5^2+512}\)
\(a,=\dfrac{3^6\cdot5^4\cdot9^4-5^{13}\cdot3^{13}\cdot5^{-9}}{3^{12}\cdot5^6+9^6\cdot5^6}=\dfrac{3^{14}\cdot5^4-5^4\cdot3^{13}}{3^{12}\cdot5^6+3^{12}\cdot5^6}\\ =\dfrac{3^{13}\cdot5^4\cdot2}{2\cdot3^{12}\cdot5^6}=\dfrac{3}{5^2}=\dfrac{3}{25}\)
\(b,=\dfrac{\left(\dfrac{2}{5}\cdot5\right)^7+\left(\dfrac{9}{4}\cdot\dfrac{16}{3}\right)^3}{2^7\cdot5^2+2^9}=\dfrac{2^7+12^3}{2^7\left(5^2+2^2\right)}=\dfrac{2^7+4^3\cdot3^3}{2^7\cdot29}=\dfrac{2^6\left(2+3^3\right)}{2^7\cdot29}=\dfrac{1}{2}\)
a) \(\dfrac{3^6\cdot3^8\cdot5^4-5^{13}\cdot3^{13}\cdot5^{-9}}{3^{12}\cdot5^6+3^{12}\cdot5^6}=\dfrac{3^{14}\cdot5^4-3^{13}\cdot5^4}{3^{12}\cdot5^6\cdot2}=\dfrac{3^{12}\cdot5^4\left(3^2-3\right)}{3^{12}\cdot5^6\cdot2}=\dfrac{3^2-3}{5^2\cdot2}=\dfrac{6}{50}=\dfrac{3}{25}\)
a) x.(-3/7)=5/21 c) -4/7 : x = -2/5 e) 3/4x - 1/2=3/7 g)(2/3x -4/9).(1/2+ -3/7:x)=0
b) x:(-2/5)= -15/16. d) 2/3x + 5/7 = 3/10 f)1/2x + 3/5x =-33/25. h)-4/7 - 5/13.-39/25+-1/42:(-5/6)
i) 2/9.[-4/45:(1/5-2/15)+1\(\frac{2}{3}\) ] - -5/27
\(a,x\left(-\frac{3}{7}\right)=\frac{5}{21}\)
\(\Rightarrow x=\frac{5}{21}:\left(-\frac{3}{7}\right)\)
\(\Rightarrow x=-\frac{5}{9}\)
\(b,x:\left(-\frac{2}{5}\right)=-\frac{15}{16}\)
\(\Rightarrow x=-\frac{15}{16}.\left(-\frac{2}{5}\right)\)
\(\Rightarrow x=\frac{3}{8}\)
\(c,-\frac{4}{7}:x=-\frac{2}{5}\)
\(\Rightarrow x=-\frac{4}{7}:\left(-\frac{2}{5}\right)\)
\(\Rightarrow x=\frac{10}{7}\)
\(d,\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)
\(\frac{\Rightarrow2}{3}x=\frac{3}{10}-\frac{5}{7}\)
\(\Rightarrow\frac{2}{3}x=-\frac{29}{70}\)
\(\Rightarrow x=-\frac{29}{70}:\frac{2}{3}\)
\(\Rightarrow x=-\frac{87}{140}\)
a, \(x.\left(-\frac{3}{7}\right)=\frac{5}{21}\)
\(\Rightarrow x=\frac{5}{21}:\left(-\frac{3}{7}\right)\)
\(\Rightarrow x=-\frac{5}{9}\)
b, \(x:\left(-\frac{2}{5}\right)=\left(-\frac{15}{16}\right)\)
\(\Rightarrow x=\left(-\frac{15}{16}\right).\left(-\frac{2}{5}\right)\)
\(\Rightarrow x=\frac{5}{8}\)
c, \(\left(-\frac{4}{7}\right):x=-\frac{2}{5}\)
\(x=\left(-\frac{4}{7}\right):\left(-\frac{2}{5}\right)\)
\(\Rightarrow x=\frac{10}{7}\)
d, \(\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)
\(\Rightarrow\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}\)
\(\Rightarrow\frac{2}{3}x=-\frac{29}{70}\)
\(\Rightarrow x=-\frac{29}{70}:\frac{2}{3}\)
\(\Rightarrow x=-\frac{87}{140}\)
e, \(\frac{3}{4}x-\frac{1}{2}=\frac{3}{7}\)
\(\Rightarrow\frac{3}{4}x=\frac{3}{7}+\frac{1}{2}\)
\(\Rightarrow\frac{3}{4}x=\frac{13}{14}\)
\(\Rightarrow x=\frac{13}{14}:\frac{3}{4}\)
\(\Rightarrow x=\frac{26}{21}\)
f, \(\frac{1}{2}x+\frac{3}{5}x=-\frac{33}{25}\)
\(\Rightarrow x\left(\frac{1}{2}+\frac{3}{5}\right)=-\frac{33}{25}\)
\(\Rightarrow\frac{11}{10}x=-\frac{33}{25}\)
\(\Rightarrow x=-\frac{33}{25}:\frac{11}{10}\)
\(\Rightarrow x=-\frac{6}{5}\)
g, \(\left(\frac{2}{3}x-\frac{4}{9}\right)\left(\frac{1}{2}+\left(-\frac{3}{7}\right):x\right)=0\)
\(\orbr{\begin{cases}\frac{2}{3}x-\frac{4}{9}=0\\\frac{1}{2}+-\frac{3}{7}:x=0\end{cases}\Rightarrow\orbr{\begin{cases}\frac{2}{3}x=\frac{4}{9}\\-\frac{3}{7}:x=-\frac{1}{2}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{4}{9}:\frac{2}{3}\\x=-\frac{3}{7}:-\frac{1}{2}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{2}{3}\\x=\frac{6}{7}\end{cases}}}\)
h, \(-\frac{4}{7}-\frac{5}{13}.-\frac{39}{25}+-\frac{1}{42}:-\frac{5}{6}=-\frac{4}{7}+\frac{3}{5}+\frac{1}{35}\)
\(=\frac{-20+21+1}{35}=\frac{2}{35}\)
i, \(\frac{2}{9}\left[-\frac{4}{45}:\left(\frac{1}{5}-\frac{2}{15}\right)+1\frac{2}{3}\right]--\frac{5}{27}=\frac{2}{9}\left(-\frac{4}{45}:\frac{3-2}{15}+\frac{5}{3}\right)+\frac{5}{27}\)
\(=\frac{2}{9}\left(-\frac{4}{45}.15+\frac{5}{3}\right)+\frac{5}{27}=\frac{2}{9}\left(-\frac{4}{3}+\frac{5}{3}\right)+\frac{5}{27}\)
\(=\frac{2}{9}.\frac{1}{3}+\frac{5}{27}=\frac{2}{27}+\frac{5}{27}=\frac{7}{27}\)