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\(1-\)\(a,\frac{7}{8}-\frac{2}{3}=\frac{21}{24}-\frac{16}{24}=\frac{5}{24}\)
\(b,\frac{7}{8}-\frac{2}{3}\times\frac{3}{4}=\frac{7}{8}-\frac{1}{2}=\frac{7}{8}-\frac{4}{8}=\frac{3}{8}\)
\(2-\)\(a,\frac{5}{8}-x=\frac{5}{9}\)
\(x=\frac{5}{8}-\frac{5}{9}\)
\(x=\frac{5}{72}\)
\(b,\frac{3}{4}:x=\frac{2}{5}\)
\(x=\frac{3}{4}:\frac{2}{5}\)
\(x=\frac{15}{8}\)
Tính hợp lý:
2 x 144 x 18 + 4 x 41 x 9 + 3 x 15 x 12=?
Help me! Mình đang cần ngay trong ngày hôm nay!
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2 x 144 x 18 + 4 x 41 x 9 + 3 x 15 x 12
=36x144+36x41+36x15
=36x(144+41+15)
=36x200
=7200
HT
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\(\frac{x}{12}\cdot\frac{2}{5}=\frac{1}{2}+\frac{2}{3}\)
\(\frac{x}{12}\cdot\frac{2}{5}=\frac{7}{6}\)
\(\frac{x\cdot2}{60}=\frac{7}{6}\)
=> \(x\cdot2=70\)
\(x=70:2\)
\(x=35\)
Trả lời :
\(\frac{x}{12}\cdot\frac{2}{5}=\frac{1}{2}+\frac{2}{3}\)
\(\frac{x}{12}\cdot\frac{2}{5}=\frac{3}{6}+\frac{4}{6}\)
\(\frac{x}{12}\cdot\frac{2}{5}=\frac{7}{6}\)
\(\frac{x}{12}=\frac{7}{6}:\frac{2}{5}\)
\(\frac{x}{12}=\frac{7}{6}\cdot\frac{5}{2}\)
\(\frac{x}{12}=\frac{35}{12}\)
\(x=\frac{35}{12}\cdot12\)
\(x=35\)
Vậy ...
Hok tốt
-Ken-
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9485 - x =41195:5 roi tim x lay 9485 : cho ket qua tim dc
(9485 - x) x 5 =41195
9485 - x =41195:5
9485 - x =8239
x =9485-8239
x =1246
Con (9 x y) x 6 + 8239
Hình như sai đề!!!
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\(\left(\frac{1}{3.5}+\frac{1}{5.7}+\frac{1}{7.9}+....+\frac{1}{19.21}\right).x=\frac{9}{7}\)
\(\left(\frac{5-3}{3.5}+\frac{7-5}{5.7}+\frac{9-7}{7.9}+...+\frac{21-19}{19.21}\right).x=\frac{9}{7}\)
\(\left[\frac{1}{2}.\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{19}-\frac{1}{21}\right)\right].x=\frac{9}{7}\)
\(\left[\frac{1}{2}.\left(\frac{1}{3}-\frac{1}{21}\right)\right].x=\frac{9}{7}\)
\(\left[\frac{1}{2}.\frac{2}{7}\right].x=\frac{9}{7}\)
\(\frac{1}{7}.x=\frac{9}{7}\)
\(\Rightarrow x=\frac{9}{7}\div\frac{1}{7}=9\)
\(\left(\frac{1}{3.5}+\frac{1}{5.7}+\frac{1}{7.9}+...+\frac{1}{19.21}\right)x=\frac{9}{7}\)
\(\Leftrightarrow\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{19}-\frac{1}{21}\right)x=\frac{9}{7}\)
\(\Leftrightarrow\left(\frac{1}{3}-\frac{1}{21}\right)x=\frac{9}{7}\)
\(\Leftrightarrow\frac{2}{7}x=\frac{9}{7}\)
\(\Leftrightarrow x=\frac{9}{2}\)
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\(A=5+10+20+40+...+1280\)
\(2\times A=10+20+40+80+...+2560\)
\(2\times A-A=\left(10+20+40+80+...+2560\right)-\left(5+10+20+40+...+1280\right)\)
\(A=2560-5=2555\)
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giải
32/9-x-5/12= 1/3 + 1/3 +1/3
32/9-x-5/12 =1
32/9-x=1+ 5/12
32/9-x=17/12
x=32/9-17/12
x=77/36
thế đó bạn
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3x+(3+5+12)=1280
3x=1260
x=420
Vậy ...