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a, \(x\) : \(\dfrac{13}{3}\) = -2,5
\(x\) = -2,5 . \(\dfrac{13}{3}\)
\(x\) = \(\dfrac{65}{6}\)
b,\(\dfrac{3}{5}\)\(x\) = \(\dfrac{1}{10}-\)\(\dfrac{1}{4}\)
\(\dfrac{3}{5}x\) = \(\dfrac{-3}{20}\)
\(x\) = \(\dfrac{-3}{20}\) : \(\dfrac{3}{5}\)
\(x\) = \(\dfrac{-1}{4}\)
c, \(\dfrac{25}{9}-\dfrac{12}{13}x=\dfrac{7}{9}\)
\(\dfrac{12}{13}x\)\(=\dfrac{25}{9}-\dfrac{7}{9}\)
\(\dfrac{12}{13}x=2\)
\(x=2:\dfrac{12}{13}\)
\(x=\dfrac{13}{6}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 2 : a, x = -36/9 = -4
b, đề sai
c, <=> -2 =< x =< -3 => x = -1
Bài 1:
a: 2/8=9/36; 2/9=8/36; 8/2=36/9; 9/2=36/8
b: -2/4=9/-18; -2/9=4/-18; 4/-2=-18/9; 9/-2=-18/4
Bài 2:
a: =>x/3=-4/3
hay x=-4
Câu b đề sai rồi bạn
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72 x 5-(2x+1)=630:9
<=> 49 x 5-2x-1=70
<=> 245-2x-1=70
<=> -2x+244=70
<=> -2x=-174
<=> x=87
tìm x biết:
a, 72.5-(2x+1)=630:9
49.5-(2x+1)=70
245-(2x+1)=70
2x+1=245-70
2x+1=175
2x=175-1
2x=174
x=174:2
x=87
Vậy x=87
b, (10-4x)+120:23=17
(10-4x)+120:8=17
(10-4x)+15=17
10-4x=17-15
10-4x=2
4x=10-2
4x=8
x=8:4
x=2
Vậy x=2
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Bài 1:
a)-54
b)-8
Bài 2:
a)(x-14):5=415:413
⇔(x-14):5=42
⇔(x-14):5=16
⇔x-14=80
⇔x=94
b)7x-15x=15-175
⇔-8x=-160
⇔x=20
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I don't now
or no I don't
..................
sorry
\(A=\frac{7}{10}+\left(\frac{7}{10}\right)^2+\left(\frac{7}{10}\right)^3\)
\(=\frac{7}{10}+\frac{49}{100}+\frac{343}{1000}\)
\(=\frac{700+490+343}{1000}\)
\(=\frac{1533}{1000}\)
\(=1,533\)