a. (3/17 - 2/345 + 5/12 ) - ( -2/345 + 3/17 - 1/12 )
b. -(49/25 +5/36 - 4/123) + (49/25 - 4/123 - 1/36)
Những câu hỏi liên quan
1. Đơn giản biểu thức:
a) (x + 17) – (24 + 35) ;
b) ( -32) – ( y + 0 ) + 20.
2. Tính nhanh các tổng sau:
a) ( 3567 – 214) – 3567;
b) ( - 2017) – ( 28 – 2017);
c) -( 269 – 357 ) + ( 269 – 357 );
d) ( 123 + 345) + (456 – 123) - [2017-(345)]
3. Bỏ dấu ngoặc rồi tính:
a) (17 – 229) + ( 17 - 25 + 229) ;
b) ( 125 – 679 + 145) – ( 125 – 679 )
4. Tìm x biết:
a) 15 – ( 4 – x) 6 ;
b) - 30 + ( 25 – x) - 1 ;
c) x – ( 12 – 25) -8 ;
d) ( x – 29 ) – ( 17 – 38 ) - 9c) x – ( - 24) 3 ; d) 22 – ( - x )...
Đọc tiếp
1. Đơn giản biểu thức:
a) (x + 17) – (24 + 35) ;
b) ( -32) – ( y + 0 ) + 20.
2. Tính nhanh các tổng sau:
a) ( 3567 – 214) – 3567;
b) ( - 2017) – ( 28 – 2017);
c) -( 269 – 357 ) + ( 269 – 357 );
d) ( 123 + 345) + (456 – 123) - [2017-(345)]
3. Bỏ dấu ngoặc rồi tính:
a) (17 – 229) + ( 17 - 25 + 229) ;
b) ( 125 – 679 + 145) – ( 125 – 679 )
4. Tìm x biết:
a) 15 – ( 4 – x) = 6 ;
b) - 30 + ( 25 – x) = - 1 ;
c) x – ( 12 – 25) = -8 ;
d) ( x – 29 ) – ( 17 – 38 ) = - 9c) x – ( - 24) = 3 ; d) 22 – ( - x ) = 12
5. Tìm số nguyên x biết:
a) x – 5 = - 1 ;
b) x + 30 = - 4;
c) x – ( - 24) = 3 ;
d) 22 – ( - x ) = 12;
e) ( x + 5 ) + ( x – 9 ) = x + 2 ;
f) ( 27 – x ) + ( 15 + x ) = x – 24 .
góp ý nè
bạn nên đăng ít một thôi mk nghĩ sẽ nhiều người trả lời hơn đó ạ.
Như mk ý, dài như bài này mk ko giải âu
Tính:
1) 3/4 - [(-3/5) - (1/12 +2/4)]
2) -6/7 . 21/12
3) (-5) . -6/20
4) -31/36 : 37/-72
5) (-5/17) : (-15)
\(\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{2}{4}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{6}{12}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\dfrac{7}{12}\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{36}{60}\right)-\dfrac{35}{60}\right]\\ =\dfrac{3}{4}-\left(-\dfrac{71}{60}\right)\\ =\dfrac{3}{4}+\dfrac{71}{60}\\ =\dfrac{35}{60}+\dfrac{71}{60}\\ =\dfrac{106}{60}\\ =\dfrac{53}{30}\)
__
\(-\dfrac{6}{7}.\dfrac{21}{12}\\ =-\dfrac{126}{84}\\ =-\dfrac{63}{42}\\ =-\dfrac{31}{14}\)
__
\(\left(-5\right).\left(-\dfrac{6}{20}\right)\\ =\dfrac{\left(-5\right).\left(-6\right)}{20}\\ =\dfrac{30}{20}\\ =\dfrac{3}{2}\)
__
\(-\dfrac{31}{36}:\left(-\dfrac{37}{72}\right)\\ =-\dfrac{31}{36}.\left(-\dfrac{72}{37}\right)\\ =\dfrac{2322}{1332}\)
__
\(\left(-\dfrac{5}{17}\right):\left(-15\right)\\ =\left(-\dfrac{5}{17}\right).\left(-\dfrac{1}{15}\right)\\ =\dfrac{5}{255}\\ =\dfrac{1}{51}\)
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\(\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{2}{4}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{6}{12}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\dfrac{7}{12}\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{36}{60}\right)-\dfrac{35}{60}\right]\\ =\dfrac{3}{4}-\left(-\dfrac{71}{60}\right)\\ =\dfrac{3}{4}+\dfrac{71}{60}\\ =\dfrac{35}{60}+\dfrac{71}{60}\\ =\dfrac{106}{60}\\ =\dfrac{53}{30}\)
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\(-\dfrac{6}{7}.\dfrac{21}{12}\\ =-\dfrac{126}{84}\\ =-\dfrac{63}{42}\\ =-\dfrac{31}{14}\)
__
\(\left(-5\right).\left(-\dfrac{6}{20}\right)\\ =\dfrac{\left(-5\right).\left(-6\right)}{20}\\ =\dfrac{30}{20}\\ =\dfrac{3}{2}\)
__________
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Tính hợp lí nếu có thể:
a)3/7+4/9+4/7+5/9
b)1/5+4/10+9/15+16/20+25/25+36/30+49/35+64/40+81/45
c)1/8+1/12+3/8+5/12
d)(1-1/2)x(1-1/3)x(1-1/4)x...x(1-100)
e)9/5:17/15+8/5:17/15
f)2/1x2+2/2x3+2/3x4+...+2/19x20
Ai nhanh nhất mình tick cho
a) 3/7 + 4/9 + 4/7 + 5/9
= ( 3/7 + 4/7 ) + ( 4/9 + 5/9 )
= 7/7 + 9/9
= 1 + 1
= 2
b)1/5 + 4/10 + 9/15 + 16/20 + 25/25 + 36/30 + 49/35 + 64/40 + 81/45
= 1/5 + 2/5 + 3/5 + 4/5 + 5/5 + 6/5 + 7/5 + 8/5 + 9/5
= ( 1/5 + 9/5 ) + ( 2/5 + 8/5 ) + (7/5 + 3/5 ) + ( 4/5 + 6/5 ) + 5/5
= 2 + 2 + 2 + 2 + 1
= 2 x 4 + 1
= 8 +1
= 9
c) 1/8 + 1/12 + 3/8 + 5/12
= ( 1/8 + 3/8 ) + ( 1/12 + 5/12)
= 4/8 + 6/12
= 1/2 + 1/2
= 2/4 = 1/2
mỏi tay rồi
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Tính hợp lý: a) (- 299) + (-300) + (-101); b) (-189) + (-200) + (-21); c) 126 + (-10) + 345 + (-116); d) 367+ (- 30) +1672 + (-337); e) 1 +(-4)+ 7+ (-10) + 13+ (-16); f) -2+7 + (-12) + 17 + (-22)+ 27; g) 34 + 35 + 36 + 37 - 14 - 15 -16 -17; h) (-213) +186 + (-14) + 217 + 54 + (-49).
g) (-457) + (-123) + 23 +237
h) 1 - 3 + 5 - 7 + ... + 41 - 43 + 45 - 47
i) 173 + (-46) + (-54) + (+27)+ (-19)
k) (-52) + 13 + 49 + (-15) + (-36) + 82
l) 3 + (-5) + 7 + (-9) + 11 + (-13) + 15 + (-17)
m) 1 + (-2) + 3 + (-4) + ... + 2001 + (-2002) + 2003
n) (-51) + (-53) + (-55) + ... + (-97) + (-99)
o) (-62) + (+1523) + (-38) + (-2523)+ (-92)
g: \(=-457+237+23-123=-220-100=-320\)
h: \(=\left(1-3\right)+\left(5-7\right)+...+\left(41-43\right)+\left(45-47\right)\)
\(=\left(-2\right)+\left(-2\right)+...+\left(-2\right)+\left(-2\right)\)
\(=-2\cdot12=-24\)
i: \(=173+27-46-54-19=200-100-19=100-19=81\)
k: \(=-52+82+49-15+13-36\)
\(=30+34-23\)
=30+11
=41
l: \(=\left(3-5\right)+\left(7-9\right)+\left(11-13\right)+\left(15-17\right)\)
\(=\left(-2\right)+\left(-2\right)+\left(-2\right)+\left(-2\right)\)
=-8
m: \(=\left(1-2\right)+\left(3-4\right)+...+\left(2001-2002\right)+2003\)
\(=2003-1-1-...-1\)
\(=2003-1001=1002\)
n:Số số hạng là:
\(\left[\left(-51\right)-\left(-99\right)\right]:1+1=49\left(số\right)\)
Tổng là \(\left(-51-99\right)\cdot\dfrac{49}{2}=-3675\)
o: \(=-62-38+1523-2523-92\)
\(=-100+1000-92=900-92=808\)
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Bài 1. Tính các tổng các số nguyên x biết
a)-2019x2020 b)a+3xa+8 (a€N)
Bài 2. Tìm x biết
a)15-(4-x)6 b)-30+(25-x) -1
c)(x+5)+(x-9)x+2
d)(27-x)+(15+x)x24
e) -5(-x+7)-3(-x-5) -4(12-x)+48
g) 7(-x-7)-5(-x-3)12(3-x)
h) (x+1)+(x+3)+(x+5)+...+(x+99)0
Bài 3.Tính hợp lý (nếu có thể) các tổng sau
a) (-359)+181+(-123)+350+(-172)
b) (-37)+54+(-70)+(-163)+246
c) (125-679+145)-(125-679)
d) (123+345)+(456-123)-[2017-(-345)]
e) 24.(16-5)-16.(24-5)
g) 24.(-157)-49.(-24)-108.76
Đọc tiếp
Bài 1. Tính các tổng các số nguyên x biết
a)-2019<x<2020 b)a+3<x<a+8 (a€N)
Bài 2. Tìm x biết
a)15-(4-x)=6 b)-30+(25-x)= -1
c)(x+5)+(x-9)=x+2
d)(27-x)+(15+x)=x=24
e) -5(-x+7)-3(-x-5)= -4(12-x)+48
g) 7(-x-7)-5(-x-3)=12(3-x)
h) (x+1)+(x+3)+(x+5)+...+(x+99)=0
Bài 3.Tính hợp lý (nếu có thể) các tổng sau
a) (-359)+181+(-123)+350+(-172)
b) (-37)+54+(-70)+(-163)+246
c) (125-679+145)-(125-679)
d) (123+345)+(456-123)-[2017-(-345)]
e) 24.(16-5)-16.(24-5)
g) 24.(-157)-49.(-24)-108.76
Bài 1 Tìm x,biết
x.3/5=2/3
x.7/17=17/8
3/4 chia x=-7/12
3/8 - 1/6.x=1/4
1/3+1/2 chia x=-4
Bài 2 Tính
-6/11 chia [3/5 . 4/11]
7/12 + 5/12 chia 6 -11/36
[4/5 + 1/2] chia [3/13 - 8/13]
[2/3 - 1/4 + 5/11] chia [5/12 + 1 -7/11]
*Dấu . là dấu nhân nha mn*
Bài 1:
a: \(x=\dfrac{2}{3}:\dfrac{3}{5}=\dfrac{2}{3}\cdot\dfrac{5}{3}=\dfrac{10}{9}\)
b: \(x=\dfrac{17}{8}:\dfrac{7}{17}=\dfrac{17}{8}\cdot\dfrac{17}{7}=\dfrac{289}{56}\)
c: \(x=-\dfrac{3}{4}:\dfrac{7}{12}=\dfrac{-3}{4}\cdot\dfrac{12}{7}=\dfrac{-63}{28}=-\dfrac{9}{4}\)
d: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{3}{8}-\dfrac{1}{4}=\dfrac{1}{4}\)
hay \(x=\dfrac{1}{4}:\dfrac{1}{6}=\dfrac{3}{2}\)
e: \(\Leftrightarrow\dfrac{1}{2}:x=-4-\dfrac{1}{3}=-\dfrac{17}{3}\)
hay \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)
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bài 1:
a) 10\17+5\-13-11\25+7\17-8\13
b) 0,3-93\7-70%0-4\7
c)1\8+1\24+1\48+...+1\2400
d) 3\41-12\17+33\49
-----------------------------
12\41-48\17+132\49
a, \(\dfrac{10}{17}\) + \(\dfrac{5}{-13}\) - \(\dfrac{11}{25}\) + \(\dfrac{7}{17}\) - \(\dfrac{8}{13}\)
= ( \(\dfrac{10}{17}\) + \(\dfrac{7}{17}\)) - ( \(\dfrac{5}{13}\) + \(\dfrac{8}{13}\)) - \(\dfrac{11}{25}\)
= \(\dfrac{17}{17}\) - \(\dfrac{13}{13}\) - \(\dfrac{11}{25}\)
= 1 - 1 - \(\dfrac{11}{25}\)
= - \(\dfrac{11}{25}\)
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b, 0,3 - \(\dfrac{93}{7}\) - 70% - \(\dfrac{4}{7}\)
= 0,3 - 0,7 - ( \(\dfrac{93}{7}+\dfrac{4}{7}\))
= - 0,4 - \(\dfrac{97}{7}\)
= - \(\dfrac{2}{5}\) - \(\dfrac{97}{7}\)
= - \(\dfrac{499}{35}\)
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c, \(\dfrac{1}{8}\) + \(\dfrac{1}{24}\) + \(\dfrac{1}{48}\)+ ...+ \(\dfrac{1}{2400}\)
= \(\dfrac{1}{2\times4}\) +\(\dfrac{1}{4\times6}\) + \(\dfrac{1}{6\times8}\) +...+ \(\dfrac{1}{48\times50}\)
= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{2}{2\times4}\) +\(\dfrac{2}{4\times6}\)+ \(\dfrac{2}{6\times8}\) +...+ \(\dfrac{2}{48\times50}\))
= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{1}{2}\) - \(\dfrac{1}{4}\) + \(\dfrac{1}{4}\) - \(\dfrac{1}{6}\) + \(\dfrac{1}{6}\) - \(\dfrac{1}{8}\) +...+ \(\dfrac{1}{48}\) - \(\dfrac{1}{50}\))
= \(\dfrac{1}{2}\) \(\times\) ( \(\dfrac{1}{2}\) - \(\dfrac{1}{50}\))
= \(\dfrac{1}{2}\) \(\times\) \(\dfrac{12}{25}\)
= \(\dfrac{6}{25}\)
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Xem thêm câu trả lời
A.(13 9/11 : 38/49 - 5 5/11 : 38/49): (49/38•5/11)
B.39 124/173•95 4/23 + 75 49/173•18/23-39 124/173•94 9/23
C.(7/12+1 25/31)•19 3/8 - 7 1/12 • 7 3/8
D.17/35•37 19/25 + 1 8/17 • 33 7/25 +(17/35-1 8/17)•32 6/25
Mong mọi người giúp mình các bài này.Mai phải nộp bài gấp
mình còn ko bt cơ mà mai nộp r
mik chỉ lm đc 1 câu thôi mong bn like cho
(13911:3849−5211:3849):(4938.511)={(13+911).4938−(5+211).4938}:(4938.511)=4938.(13−5+911−211):(4938.511)=4938.(8+711):(4938.511)=(8+711):511=19
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