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[3,8 : (x + 1,05)] : \(\frac{1}{3}\)= 2\(\frac{1}{9}\)

\(\left[\frac{19}{5}:\left(x+\frac{21}{20}\right)\right]:\frac{1}{3}=\frac{19}{9}\)

\(\frac{19}{5}:\left(x+\frac{21}{20}\right)=\frac{19}{9}.\frac{1}{3}=\frac{19}{27}\)

\(x+\frac{21}{20}=\frac{19}{5}:\frac{19}{27}=\frac{27}{5}\)

\(x=\frac{27}{5}-\frac{21}{20}\)

\(x=\frac{87}{20}\)

Tìm x

\(9+\frac{1}{x}+p:89\times97\div9+x=914,978,000\)

=(4/6+14/6)+(7/13+19/13)+(17/9+1/9)

=18/6+26/13=18/9

=3+2+2=7

bai 3

1/3 + 1/4 + 1/6 = 9/12

3,8 : (x+1,05) = 19/27

x+1,05=3,8:19/27

x+1,05=5,4

x=5,4-1,05

x=4,35

3,8:(x+1,05)=19/7

x+21/20=19/5.7/19

x+21/20=5/7

x=5/7-21/20

x=-53/140

Xin lỗi, mình nhầm đề bài, bài của mình sai đó!

a) (x - 3)(y - 3) = 9 = 1.9 = 3.3

Lập bảng:

Vậy ...

b) A = \(\frac{10^{19}+1}{10^{20}+1}\) => 10A = \(\frac{10^{20}+10}{10^{20}+1}=1+\frac{9}{10^{20}+1}\)

B = \(\frac{10^{20}+1}{10^{21}+1}\) => 10B = \(\frac{10^{21}+10}{10^{21}+1}=1+\frac{9}{10^{21}+1}\)

Do \(10^{20}+1< 10^{21}+1\) => \(\frac{9}{10^{20}+1}>\frac{9}{10^{21}+1}\) => 10A > 10B => A > B

[ 3,8 : ( x + 1,05 ) ] : 1/3 = 2 1/9 

19/5 : ( x + 1,05 )           = 21/9 x 1/3

19/5 : ( x + 1,05)            = 7/9

          x + 1,05                = 19/5 : 7/9 

          x + 21/20             = 171/35

             x                        = 171/35 - 21/20

             x                        = 228/49

[ 3,8 : ( x + 1,05 ) ] : 1/3 = 2 1/9 

=>  3,8 : ( x+1,05) = 19/9 x 1/ 3 = 19/27

=> x + 1,05 = 3,8 : 19/27 = 5,4

=> x= 5,4-1,05 = 4,35

\(\left(3,8:\left(x+1,05\right)\right):\frac{1}{3}=\frac{21}{9}\)

\(=>3,8:\left(x+1,05\right)=\frac{7}{9}\)

\(=>x+1,05=\frac{171}{35}\)

\(=>x=\frac{537}{140}\)

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