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\(\dfrac{x}{17}+\dfrac{19}{34}=2\dfrac{1}{2}\)
\(\Rightarrow\dfrac{x}{17}+\dfrac{19}{24}=\dfrac{5}{2}\)
\(\Rightarrow\dfrac{x}{17}=\dfrac{33}{17}\Rightarrow x=33\)
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x/17 + 19/34 = 2 1/2
x/17 + 19/34 = 5/2
x/17 = 5/2 - 19/34
x/17 = 33/17
Vậy x = 33
x/17 + 19/34 =2 1/2
x/17 + 19/34 =5/2
x/17 = 5/2 - 19/34
x/17 = 33/17
Vậy x = 17
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a) = 17/19 - 17/19 + 27/35 + 35/35 = 0 + 62/35
b) = 1/3 x 4/5 + 1/3 x6/5 + 1/3 x 2 = 1/3(4/5 + 6/5 + 2) = 1/3 x 4 = = 4/3
c) 4/7 x 2/9 + 4/7 x 7/9 + 2/3 = 4/7 x (2/9 + 7/9) + 2/3 = 4/7 x 1 + 2/3 = 26/21
A) 17/19 - 17/19 + 27/35 + 35/35 = 0 + 62/35
B) 1/3 x 4/5 + 1/3 x 6/5 + 1/3 x 2 = 1/3 x(4/5 + 6/5 x 2 ) = 1/3 x 4 = 4/3
c) TƯƠNG TỰ CÂU A VÀ B
* HOKTOT*
NHA
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\(\frac{x}{17}+\frac{19}{34}=2\frac{1}{2}\)
\(\Rightarrow\frac{2x}{34}+\frac{19}{34}=2\frac{1}{2}\)
\(\Rightarrow\frac{2x+19}{34}=2\frac{1}{2}\Rightarrow2x+19=34.2\frac{1}{2}\Rightarrow2x+19=85\Rightarrow2x=66\Rightarrow x=33\)
b) 30% * x + x =52
=> 3/10 * x + x=52
=> x * ( 3/10 + 1 ) = 52
=> x *1,3 = 52
=> x = 52 : 1,3 =40
\(\frac{x}{17}+\frac{19}{34}=2\frac{1}{2}=\frac{5}{2}\)
\(\frac{x}{17}=\frac{5}{2}-\frac{19}{34}\)
\(\frac{x}{17}=\frac{170}{68}-\frac{38}{68}\)
\(\frac{x}{17}=\frac{132}{68}\)
=>\(x.68=17.132\)
\(x.68=2244\)
\(x=2244:68\)
\(x=33\)
vậy x=33
dấu"." chính là phép nhân đó em!!!
chúc em học giỏi...
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a) 19 x 64 + 76 x 34
= 19 x 64 + 19 x 136
= 19.(64 + 136)
= 19 . 200
= 3800
a) 19 x 64 + 76 x 34
= 19 x 64 + 19 x 136
= 19.(64 + 136)
= 19 . 200
= 3800
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Bài 1:
23 x X -782 = 6x X+17
23 x X - 6x X=17+782
17x X=799
X = 799 : 17
X=47
Bài 2:
a ) abc x 5= 1000 + abc
abc x 4=1000
abc =1000:4
abc =250
b ) abc x 8 + abc = 6000+abc
abc x 8 =6000
abc = 6000:8
abc=750
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\(\left(\frac{2}{11\times13}+\frac{2}{13\times15}+\frac{2}{15\times17}+\frac{2}{17\times19}+\frac{2}{19\times21}\right)\times462-x=19\)
\(\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)\times462-x=19\)
\(\left(\frac{1}{11}-\frac{1}{21}\right)\times462-x=19\)
\(\frac{10}{231}\times462-x=19\)
\(20-x=19\)
\(\Rightarrow x=20-19=1\)
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a \(\dfrac{5}{12}\times\dfrac{4}{9}\) + \(\dfrac{4}{9}\times\dfrac{7}{12}\)
= \(\dfrac{4}{9}\times\left(\dfrac{5}{12}+\dfrac{7}{12}\right)\)
= \(\dfrac{4}{9}\times\dfrac{12}{12}\)
= \(\dfrac{4}{9}\)
b(\(\dfrac{13}{21}\times\dfrac{7}{8}-\dfrac{12}{21}\times\dfrac{7}{8}\)) x 12
(\(\dfrac{7}{8}\times\left(\dfrac{13}{21}-\dfrac{12}{21}\right)\))x 12
\(\dfrac{7}{8}\times\dfrac{1}{21}\) x 12
\(\dfrac{139}{14}\)
\(\dfrac{7}{11}+\dfrac{3}{4}+\dfrac{4}{11}+\dfrac{8}{17}+\dfrac{1}{4}+\dfrac{18}{34}\)
=\(\left(\dfrac{7}{11}+\dfrac{4}{11}\right)+\left(\dfrac{3}{4}+\dfrac{1}{4}\right)\) + \(\dfrac{18}{34}\)
=1 + 1 + \(\dfrac{18}{34}\)
=\(\dfrac{34}{17}\)