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1+1=2
2+2=4
3+3=6
4+4=8
5+5=10
15+15=30
25+350=375
2451-2144=307
597.622:252.533=785400,881
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\(B=\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{9.11}+\frac{1}{11.13}\)
\(2B=2\left(\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{11.13}\right)\)
\(2B=\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{11.13}\)
\(2B=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{11}-\frac{1}{13}\)
\(2B=\frac{1}{3}-\frac{1}{13}\)
\(2B=\frac{10}{39}\)
\(B=\frac{5}{39}\)
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Theo mk là như dzậy:
15 = 3 * 5
35 = 5 * 7
63 = 7 * 9
?= 9 * 11
143 = 11 * 13
Dzậy ? = 99
k mk cái nha
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1 + 1 = 2
2 + 2 = 4
6 + 6 = 12
9 + 9 = 18
10 + 10 = 20
9 x 143 = 1287
90 : 45 = 2
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\(\frac{x}{1.3}+\frac{x}{3.5}+\frac{x}{5.7}+.....+\frac{x}{9.11}+\frac{x}{11.13}=\frac{6}{13}\)
=>\(\frac{x}{1}-\frac{x}{3}+\frac{x}{3}-\frac{x}{5}+\frac{x}{5}-\frac{x}{7}+......+\frac{x}{9}-\frac{x}{11}+\frac{x}{11}-\frac{x}{13}=\frac{12}{13}\)
\(\frac{x}{1}-\frac{x}{13}=\frac{12}{13}\)
x.12/13=12/13 => x=1
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49 786 + 38 679 = 88465
72 513 - 39 786 = 32727
2 143 x 107 = 229301
13 578 : 236 = \(\frac{6789}{118}\)
49786 + 38697 = 88483
72513 -39785 = 32727
2143 * 107 = 229301
13578 : 236 = 57 dư
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ez game
4=1
4=1 nha