Bài 1 : Tính :
a, 12 : { 350 : [ 500 - ( 125 + 35 . 7 ) ] }
b, 100 : { 250 : [ 450 - ( 4 . \(5^2\). \(2^2\). 25 ) ] }
c, \(\frac{5.6^{13}.2^3+4^8.9^6}{6.2^{15}.3^{12}}\)
Những câu hỏi liên quan
Bài 1 : Tính :
a, 12 : { 350 : [ 500 - ( 125 + 35 . 7 ) ] }
b, 100 : { 250 : [ 450 - ( 4. \(5^2\)- \(2^2\). 25 ) ] }
c, \(\frac{5.6^{13}.2^3+4^8.9^6}{6.2^{15}.3^{12}}\)
Bài 1 : Tính : \(\frac{5.6^{13}.2^3+4^8.9^6}{6.2^{15}.3^{12}}\)
\(\frac{5.6^{13}.2^3+4^8.9^6}{6.2^{15}.3^{12}}=\frac{5.3^{13}.2^{13}.2^3+2^{16}.3^{12}}{2.3.2^{15}.3^{12}}=\frac{5.3^{13}.2^{16}+2^{16}.3^{12}}{2^{16}.3^{13}}=\frac{2^{16}.3^{12}.\left(5.3+1\right)}{2^{16}.3^{12}.3}=\frac{5.3+1}{3}=\frac{16}{3}\)
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a,12/7*7/4+35/11:245/12
b,(3/4+8/3).(7/4-6/4):(6/5+12/5+1/5)
c,17/23.8/16.23/17.(-80).3/4
d,D= 1^2 / 1.2 . 2^2 / 2.3 . 3^2 / 3.4 . 4^2 / 4.5 . 5^2 / 5.6 . 6^2 / 6.7 . 7^2 . 7.8 . 8^2 / 8.9 . 9^2 / 9.10
nhanh cho mình nha
Bài 1: Tính nhanh:a) 2 . 13 . 15 c) 8 . 9 . 125 e) 64 . 125 . 12 g) 4 . 32 . 25 . 125b) 25 . 17 . 4 d) 7 . 24 . 25 f) 72 . 125 . 3Bài 2: Tính nhanh :a) 81. 17 - 2 . 17 + 21 . 17b) 13 . 24 + 37 . 6 .4 + 12 . 50 . 2c) 2 . 18 . 14 +3 . 17 . 12 + 4 . 69 . 9d) 31 . ( 532 + 478 ) + 69 . ( 389 +621 )e) 3 + 6 +8 +10 +12 + ... +104Bài 3: Tính tổng ác số hạng của dãy số sau :A 1 + 2 + 5 +8 + 11 + ... + 100 + 103
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Bài 1: Tính nhanh:
a) 2 . 13 . 15 c) 8 . 9 . 125 e) 64 . 125 . 12 g) 4 . 32 . 25 . 125
b) 25 . 17 . 4 d) 7 . 24 . 25 f) 72 . 125 . 3
Bài 2: Tính nhanh :
a) 81. 17 - 2 . 17 + 21 . 17
b) 13 . 24 + 37 . 6 .4 + 12 . 50 . 2
c) 2 . 18 . 14 +3 . 17 . 12 + 4 . 69 . 9
d) 31 . ( 532 + 478 ) + 69 . ( 389 +621 )
e) 3 + 6 +8 +10 +12 + ... +104
Bài 3: Tính tổng ác số hạng của dãy số sau :
A = 1 + 2 + 5 +8 + 11 + ... + 100 + 103
a)2.13.15=(2.15).13
=30.13
=390
8.9.125
=(8.125).9
=1000.9
=9000
Bài 4: Tính nhanh:a, A left(frac{84}{13}right)^2+left(frac{35}{13}right)^2 b, B frac{12-frac{12}{7}-frac{12}{289}-frac{12}{85}}{4-frac{4}{7}-frac{4}{289}-frac{4}{85}}divfrac{3+frac{3}{13}+frac{3}{169}+frac{3}{91}}{7+frac{7}{13}+frac{7}{169}+frac{7}{91}}c, C frac{1times2+2times4+3times6+4times8+5times10}{3times4+6times8+9times12+12times16+15times20}
Đọc tiếp
Bài 4: Tính nhanh:
a, A =\(\left(\frac{84}{13}\right)^2+\left(\frac{35}{13}\right)^2\)
b, B = \(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}\div\frac{3+\frac{3}{13}+\frac{3}{169}+\frac{3}{91}}{7+\frac{7}{13}+\frac{7}{169}+\frac{7}{91}}\)
c, C =\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)
bài 5: tính giá trị biểu thức sau một cách hợp lí
A = -7/21 + ( 1+1/3) B=2/15 +(5/9+ -6/9)
C=9-1/5 + 3/12 ) + -3/4
bài 6
a) x + 7/8 = 13/12 b) - (-6)/12 - x = 9/48
c) x+ 4/6 = 5/25 - (-7)/15 c) x + 4/5 = 6/20 - (-7)/3
`5`
`a, -7/21 +(1+1/3)`
`=-7/21 + ( 3/3 + 1/3)`
`=-7/21+ 4/3`
`=-7/21+ 28/21`
`= 21/21`
`=1`
`b, 2/15 + ( 5/9 + (-6)/9)`
`= 2/15 + (-1/9)`
`= 1/45`
`c, (9-1/5+3/12) +(-3/4)`
`= ( 45/5-1/5 + 3/12)+(-3/4)`
`= ( 44/5 + 3/12)+(-3/4)`
`= 9,05 +(-0,75)`
`=8,3`
`6`
`x+7/8 =13/12`
`=>x= 13/12 -7/8`
`=>x=5/24`
`-------`
`-(-6)/12 -x=9/48`
`=> 6/12 -x=9/48`
`=>x= 6/12-9/48`
`=>x=5/16`
`---------`
`x+4/6 =5/25 -(-7)/15`
`=>x+4/6 =1/5 + 7/15`
`=> x+ 4/6=10/15`
`=>x=10/15 -4/6`
`=>x=0`
`----------`
`x+4/5 = 6/20 -(-7)/3`
`=>x+4/5 = 6/20 +7/3`
`=>x+4/5 = 79/30`
`=>x=79/30 -4/5`
`=>x= 79/30-24/30`
`=>x= 55/30`
`=>x= 11/6`
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\(5)\)
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=1\)
\(--------------\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{18}{135}+\dfrac{-15}{135}\)
\(B=\dfrac{1}{45}\)
\(------------\)
\(C=9-\dfrac{1}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{44}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{528}{60}+\dfrac{15}{60}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{83}{10}\)
\(6)\)
\(a)\) \(x+\dfrac{7}{8}=\dfrac{13}{12}\)
\(x=\dfrac{13}{12}-\dfrac{7}{8}\)
\(x=\dfrac{104}{96}-\dfrac{84}{96}\)
\(x=\dfrac{5}{24}\)
\(b)\) \(\dfrac{-6}{12}-x=\dfrac{9}{48}\)
\(\dfrac{-1}{2}-x=\dfrac{3}{16}\)
\(x=\dfrac{-1}{2}-\dfrac{3}{16}\)
\(x=\dfrac{-8}{16}-\dfrac{3}{16}\)
\(x=\dfrac{-11}{16}\)
\(c)\) \(x+\dfrac{4}{6}=\dfrac{5}{25}-\left(-\dfrac{7}{15}\right)\)
\(x+\dfrac{4}{6}=\dfrac{5}{25}+\dfrac{7}{15}\)
\(x+\dfrac{4}{6}=\dfrac{75}{375}+\dfrac{105}{375}\)
\(x+\dfrac{4}{6}=\dfrac{12}{25}\)
\(x=\dfrac{12}{25}-\dfrac{4}{6}\)
\(x=\dfrac{72}{150}-\dfrac{100}{150}\)
\(x=\dfrac{-14}{75}\)
\(d)\) \(x+\dfrac{4}{5}=\dfrac{6}{20}-\left(-\dfrac{7}{3}\right)\)
\(x+\dfrac{4}{5}=\dfrac{6}{20}+\dfrac{7}{3}\)
\(x+\dfrac{4}{5}=\dfrac{18}{60}+\dfrac{140}{60}\)
\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
\(x=\dfrac{79}{30}-\dfrac{4}{5}\)
\(x=\dfrac{79}{30}-\dfrac{24}{30}\)
\(x=\dfrac{11}{6}\)
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Giải:
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=\dfrac{21}{21}=1\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{6}{45}+\dfrac{-5}{45}\)
\(B=\dfrac{1}{45}\)
\(C=\left(9-\dfrac{1}{5}+\dfrac{3}{12}\right)+\dfrac{-3}{4}\)
\(C=\left(\dfrac{44}{5}+\dfrac{1}{4}\right)+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{166}{20}\)
Bài 6:
\(a)x+\dfrac{7}{8}=\dfrac{13}{12}\)
⇔\(x=\dfrac{13}{12}-\dfrac{7}{8}=\dfrac{5}{24}\)
\(b)\dfrac{-6}{12}-x=\dfrac{9}{48}\)
⇔\(x=\dfrac{-6}{12}-\dfrac{9}{48}=\dfrac{-11}{16}\)
\(c)x+\dfrac{4}{6}=\dfrac{5}{25}-\dfrac{-7}{15}\)
\(\Leftrightarrow x+\dfrac{2}{3}=\dfrac{2}{3}\)
\(\Leftrightarrow x=\dfrac{2}{3}-\dfrac{2}{3}=0\)
\(d)x+\dfrac{4}{5}=\dfrac{6}{20}-\dfrac{-7}{3}\)
⇔\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
⇔\(x=\dfrac{79}{30}-\dfrac{4}{5}=\dfrac{11}{6}\)
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tính:
a) 3/7 + 1/2 - -3/70 , b ) 3/5 + 1/ 25 - 35/100
c) 5/12 - 3/-16 + 3/4 d) 5/15 + 4/-15 + 6/15 + -3/5 + 2/21 + -10/21 + 3/20 dấu âm -
e) 5/15 + 4/-12 + 1/7 + 1/-6
f) 42/46 + 250/46 + -2121/2525 + -125125/143143
2. tìm x biết :
a)3/4 - x = 1
Bài 4 : Tính nhanh :
a: 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
b: 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
c: 5 x 7 x 77 - 7 x 60 + 49 x 25 - 15 x 42
Bài 5 : Tìm x , biết :
a: x : [( 1800 + 600 ) : 30 ] = 560 : ( 315 - 35 )
b: [( 250 - 25 ) : 15 ] : x = ( 450 - 60 ) : 130
Bạn dùng tính chất phân phối, giao hoán để làm nhé
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1) a) 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
= 39 x (53 + 47) - 21 x (53 - 47)
= 39 x 100 - 21 x 6
= 3900 - 126
= 3774
b) 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
= 1272 + 2088 - 960
= 3360 - 960
= 2400
c) 5 x 7 x 77 - 7 x 60 + 47 x 25 - 15 x 42
= 2695 - 420 + 1175 - 630
= 2275 + 545
= 2820
2) a) x : [(1800 + 600) : 30] = 560 : (315 - 35)
x : (2400 : 30) = 560 : 280
x : 80 = 2
x = 2 x 80
=> x = 160
b) [(250 - 25) : 15] : x = (450 - 60) : 130
225 : 15 : x = 390 : 130
15 : x = 3
x = 15 : 3
=> x = 5
Học tốt!!!
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Xem thêm câu trả lời
Bài 1: Tính:
A= ((2^12 . 3^5 - 4^6 . 9^3 ) / 9( 2^2 . 3 )^6 + (8^4 . 3^5))) - ((5^10 . 7^3 - 25^2 . 49^2) / (( 125 . 7 )^3 + 5^9 . 14^3))
B= (2^9 . 27^3 + 15 . 4^9 . 9^4) / (6^9 . 2^0 + 12^10)