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3/2-3/2:(-1/8)
=3/2-3/2.(-8)
=3/2(1+8)
=3/2x9
=27/2
\(\frac{3}{2}-\frac{3}{2}:-\frac{1}{2^3}\)
\(=\frac{3}{2}-\frac{3}{2}.\frac{-2^3}{1}\)
\(=\frac{3}{2}-\left(-12\right)\)
\(=\frac{3}{2}+\frac{24}{2}\)
\(=\frac{27}{2}\)
hok tốt!!!
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a) 3/4x16/9-7/5:(-21/20)
=4/3-(-4/3)
=8/3
b)=7/3-1/3x[-3/2+(2/3+2)]
=7/3-1/3x[-3/2+8/3]
=7/3-1/3x7/6
=7/3-7/18
=35/18
c)=(20+37/4):9/4
=117/4:9/4
=13
d)=6-14/5x25/8-8/5:1/4
=6-35/4-32/5
=-11/4-32/5
=-183/20
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a,\(\frac{10x125x4x25x8}{0,8x0,04x1,25x25+0,6524+0,3476}\)
=\(\frac{10x\left(125x8\right)x\left(4x25\right)}{\left(0,8x1,25\right)x\left(0,04x25\right)+\left(0,6524+0,3476\right)}\)
=\(\frac{10x1000x100}{1x1+1}\)
=\(\frac{1000000}{2}\)=\(500000\)
b,\(\frac{3}{4}\)x X + 1,25 x X + 50% x X = 12,5 x 0,8
0,75 x X + 1,25 x X + 0,5 x X = 10
(0,75 + 1,25 + 0,5) x X = 10
2,5 x X = 10
X = 10: 2,5 =4
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toán lp 7 đúng k k pk toán lp 1 đâu
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\(A=\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+...+\frac{1}{49\cdot50}\)
\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{50}\)
\(A=1-\frac{1}{50}\)
\(A=\frac{49}{50}\)
\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{50}\)
\(A=1-\frac{1}{50}\)
\(A=\frac{49}{50}\)
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\(\frac{1}{6}+\frac{2}{3}\)
\(=\frac{1}{6}+\frac{4}{6}\)
\(=\frac{1+4}{6}=\frac{5}{6}\)
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\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)
\(=1-\frac{1}{100}< 1\)
\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{99.100}\)
\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}\)
\(=1-\frac{1}{100}\)
\(=\frac{99}{100}< 1\)
\(\frac{3}{4}+\frac{1}{2}+\frac{4}{5}=\frac{41}{20}\)