Bài 1: Tính hợp lí nếu có:
a) [ ( 17/15 - 4/30 ) :5/6 ] : [ 102/25 : ( 17/25 . 1/15 ) ]
b) ( 1284/1391 + 212121/656565) : ( 27/13 . 3 )
Thanks
Những câu hỏi liên quan
Tính hợp lý
a. M=\(\left(\dfrac{1284}{1391}+\dfrac{212121}{656565}\right):\left(\dfrac{27}{13}\cdot3\right)\)
a. \(M=\left(\frac{12}{13}+\frac{21}{65}\right):\frac{81}{13}\)
\(M=\left(\frac{120}{130}+\frac{42}{130}\right).\frac{13}{81}\)
\(M=\frac{81}{65}.\frac{13}{81}\)
\(M=\frac{1}{5}\)
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M=(12.107/13.107 + 21.10101/65.10101):27.3/13=(12/13 + 21/65):27.3/13
=[(12.5+21)/65]:27.3/13
=81/13.5 : 27.3/13 =81/(5.27.3)=1/5
Đs: M=1/5
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Tính hợp lý
a. M=\(\left(\dfrac{1284}{1391}+\dfrac{212121}{656565}\right):\left(\dfrac{27}{13}\cdot3\right)\)
\(M=\left(\dfrac{12}{13}+\dfrac{21}{65}\right):\dfrac{9}{13}=\dfrac{81}{65}\cdot\dfrac{13}{9}=\dfrac{1}{5}\cdot9=\dfrac{9}{5}\)
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Thực hiện phép tính(tính hợp lí nếu có thể)
4/5+(-5)/4 -1/3+2/5-5/6 2/3-5/7.14/25 (2/5-5/6):8/15-(-1)^2
-3/13+(-7)/17+(-5)/19+(-10)/13+24/17+(-14)/19
\(\dfrac{4}{5}\)+\(\dfrac{-5}{4}\)=\(\dfrac{0}{4}\)
\(\dfrac{-1}{3}\)+\(\dfrac{2}{5}-\dfrac{5}{6}\)=\(\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}\)=\(\dfrac{-23}{30}\)
\(\dfrac{2}{3}-\dfrac{5}{7}.\dfrac{14}{25}\)=\(\dfrac{2}{3}-\dfrac{2}{5}\)=\(\dfrac{10}{15}-\dfrac{6}{15}\)=\(\dfrac{4}{15}\)
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a: \(=\dfrac{16-25}{20}=\dfrac{-9}{20}\)
b: \(=\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}=-\dfrac{23}{30}\)
c: \(=\dfrac{2}{3}-\dfrac{1}{5}\cdot2=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10-6}{15}=\dfrac{4}{15}\)
d: \(=\dfrac{12-25}{30}\cdot\dfrac{15}{8}-1=\dfrac{-13}{16}-1=\dfrac{-29}{16}\)
e: \(=\dfrac{-3}{13}-\dfrac{10}{13}-\dfrac{7}{17}+\dfrac{24}{17}-\dfrac{5}{19}-\dfrac{14}{19}=-1\)
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Tính hợp lí
1) -145.(13 - 57) + 57.(10 -145)
2) 17.(15 - 16) + 16.( 17- 20)
3) -38.(25 - 4) + 25.(-4 + 38 )
4) 23.(145 - 17) - 145.(23 - 6)
5) 24.(15 - 4) + 4.(24 - 15)
6) 199.(15 - 17) - 199.(-17 + 5)
7) -39.(5 - 99) + 99.(10 - 39)
tính nhanh:a) 15/14-(17/13-87+5/4)+(17/23-15/14+1/4) b) 1/25-4/27+(-23/27+-1/25-5/43)+5/43-4/7
1,Tính giá trị biểu thức
a, 13 . 17 - 256 : 16 + 14 : 7 - 1
b, 15 . 24 - 14 . 5 . (145 : 5 - 27)
c, 15 . 8 - (17 - 30 + 83) - 144 : 6
d,18 - 4 . (27 - 90 + 73) : 10
2,Tìm x
a, 315 - (135 - x)=215
b, x - 320 : 32 = 25 . 16
c, 3 . x - 2018 : 2 = 23
d, 280 - 9 . x - x = 80
e, 38 . x - 12 . x - x . 16 = 40
Giúp mình với nhé,mình đang cần gấp !!
2,
a) \(315-\left(135-x\right)=215\)
\(\Rightarrow135-x=315-215\)
\(\Rightarrow135-x=100\)
\(\Rightarrow x=135-100\)
\(\Rightarrow x=35\)
b) \(x-320:32=25\cdot16\)
\(\Rightarrow x-10=5^2\cdot4^2\)
\(\Rightarrow x-10=20^2\)
\(\Rightarrow x-10=400\)
\(\Rightarrow x=410\)
c) \(3\cdot x-2018:2=23\)
\(=3\cdot x-1009=23\)
\(\Rightarrow3\cdot x=1032\)
\(\Rightarrow x=1032:3\)
\(\Rightarrow x=344\)
d) \(280-9\cdot x-x=80\)
\(\Rightarrow280-x\cdot\left(9+1\right)=80\)
\(\Rightarrow280-10\cdot x=80\)
\(\Rightarrow10\cdot x=280-80\)
\(\Rightarrow10\cdot x=200\)
\(\Rightarrow x=20\)
e) \(38\cdot x-12\cdot x-x\cdot16=40\)
\(\Rightarrow x\cdot\left(38-12-16\right)=40\)
\(\Rightarrow x\cdot10=40\)
\(\Rightarrow x=40:10\)
\(\Rightarrow x=4\)
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Giúp mình với mấy bạn
Tính bằng cách hợp lí nhất:
1).25 va 2/13-(15/17+15 va 2/3)
2).3 va 1/11*27/46*1 va 6/17*2 va 4/9
3).75,284*15,137*(9,5-4,75*2)+231*(7,35+2,65)
7 tháng 11 2023 lúc 19:22
1.Tính:a) 13 + 21 . 5 - (198 : 11 -8)b) 272 : 16 - 5 + 4 . (30 - 5 - 255 : 17)c) 15 . 24 - 14 . 5 . (145 : 5 - 27)d) 18 . 3 - 18 . 2 + 3 . (51 : 17)e) (64 + 115 + 36) - 25 . 8 . 6 . 22 . 3 + 42f) 15 . 8 - (17 - 30 + 83) - 144 : 6g) 250 : 50 - (46 - 75 + 54) : 5h) 13 . (17 - 95 + 83) - 144 : 6i) 140 - 180 . (47 - 90 + 43) + 7j) 24 . (15 + 30 + 85 - 120) : 102.Tínha) 22 . 3 - 4 b) 16 - 23 . 2 c) 42 - 4 . 2d) 33 - 2 . 32 e)...
Đọc tiếp
1.Tính:
a) 13 + 21 . 5 - (198 : 11 -8)
b) 272 : 16 - 5 + 4 . (30 - 5 - 255 : 17)
c) 15 . 24 - 14 . 5 . (145 : 5 - 27)
d) 18 . 3 - 18 . 2 + 3 . (51 : 17)
e) (64 + 115 + 36) - 25 . 8 . 6 . 22 . 3 + 42
f) 15 . 8 - (17 - 30 + 83) - 144 : 6
g) 250 : 50 - (46 - 75 + 54) : 5
h) 13 . (17 - 95 + 83) - 144 : 6
i) 140 - 180 . (47 - 90 + 43) + 7
j) 24 . (15 + 30 + 85 - 120) : 10
2.Tính
a) 22 . 3 - 4 b) 16 - 23 . 2 c) 42 - 4 . 2
d) 33 - 2 . 32 e) 72 - 9 . 22 f) 22 . 3 + 42
2:
a: \(2^2\cdot3-4=4\cdot3-4=12-4=8\)
b: \(16-2^3\cdot2=16-2^4=16-16=0\)
c: \(4^2-4\cdot2=16-8=8\)
d: \(3^3-2\cdot3^2=27-2\cdot9=27-18=9\)
e: \(7^2-9\cdot2^2=49-9\cdot4=49-36=13\)
f: \(2^2\cdot3+4^2=4\cdot3+16=12+16=28\)
Bài 1:
a: \(13+21\cdot5-\left(198:11-8\right)\)
\(=13+105-18+8\)
=21+87
=108
b: \(272:16-5+4\cdot\left(30-5-255:17\right)\)
\(=17-5+4\cdot\left(30-5-15\right)\)
\(=12+4\cdot10=12+40=52\)
c: \(15\cdot24-14\cdot5\cdot\left(145:5-27\right)\)
\(=360-70\left(29-27\right)\)
=360-140
=220
d: \(18\cdot3-18\cdot2+3\cdot\left(\dfrac{51}{17}\right)\)
\(=18\left(3-2\right)+3\cdot3\)
=18+9
=27
e: \(64+115+36-25\cdot8\cdot6\cdot2^2\cdot3+4^2\)
\(=100+115-200\cdot6\cdot4\cdot3+16\)
\(=231-14400=-14169\)
f: \(15\cdot8-\left(17-30+83\right)-144:6\)
\(=120-24-\left(100-30\right)\)
=96-70
=26
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25 2/13 -(15/17+ 15 2/3)
5/30 + 15/90+250/150+350/210+45/270
3 1/11 nhân 27/46 nhân 1 6/17 nhân 2 4/9
\(25\frac{2}{13}-\left(\frac{15}{17}+15\frac{2}{3}\right)=\frac{327}{13}-\left(\frac{15}{17}+\frac{47}{3}\right)\)
\(=\frac{327}{13}-\frac{844}{51}\)
\(=\frac{5705}{663}\)
\(\frac{5}{30}+\frac{15}{90}+\frac{250}{150}+\frac{350}{210}+\frac{45}{270}=\frac{1}{6}+\frac{1}{6}+\frac{5}{3}+\frac{5}{3}+\frac{1}{6}\)
\(=\frac{3}{6}+\frac{10}{3}\)
\(=\frac{1}{2}+\frac{10}{3}\)
\(=\frac{23}{6}\)
\(3\frac{1}{11}.\frac{27}{46}.1\frac{6}{17}.2\frac{4}{9}=\frac{34}{11}.\frac{27}{46}.\frac{23}{17}.\frac{22}{9}\)
\(=\frac{68}{9}.\frac{27}{34}\)
\(=6\)
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