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a, \(x=-\frac{21}{20}-\frac{-7}{15}\)
\(x=\frac{-7}{12}\)
b, \(\frac{7}{2}-x=\frac{-21}{20}:\frac{5}{4}\)
\(\frac{7}{2}-x=\frac{-21}{25}\)
\(x=\frac{7}{2}-\frac{-21}{25}\)
\(x=\frac{217}{50}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{-x}{21}=\dfrac{20}{7}\)
\(\Rightarrow x=\dfrac{-\left(20.21\right)}{7}\)
\(\Rightarrow\)\(x=-60\)
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7/2 - x=-21/20:5/4
7/2 - x= -21/25
X=7/2 - (-21/25)
X=2117/50
Nha bạn
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Vì \(\frac{-x}{21}=\frac{20}{7}\)suy ra -x . 7.=21. 20
x=\(\frac{21.20}{7}\)
x=60
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a 25 phần 41
b 9
c 1 phần 12
d 12
e 14 phần 15
f 24 phần 7
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a) x/7 = 6/21
<=> x . 21 = 7 . 6
<=> x . 21 = 42
<=> x = 42 : 21
<=> x = 2
b) -5/y = 20/28
<=> y . 20 = -5 . 28
<=> y . 20 = -140
<=> y = -140 : 20
<=> y = -7
Vậy y = -7
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\(\frac{-x}{21}=\frac{20}{7}\)
\(\Rightarrow-x.7=21.20\)
\(\Rightarrow-x.7=420\)
\(\Rightarrow-x=420:7\)
\(\Rightarrow-x=-60\)
\(\frac{-x}{21}=\frac{20}{7}\)
\(\Rightarrow-x.7=20.21\)
\(\Rightarrow-7x=420\)
\(\Rightarrow x=420:-7\)
\(\Rightarrow x=-60\)
Vậy \(x=-60\)
Chúc bạn học tốt !!!
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a: =>x=7-20=-13
b: =>x=-18+12=-6
c: =>x=9 hoặc x=-6
d: =>x=0 hoặc x=4
e: =>6-x=13-3+14=24
=>x=-18
Câu g và h đề thiếu rồi bạn
-x/21 = 20/7
7 * ( -x ) = 21 * 20
7 ( -x ) = 420
-x = 420/7 = 60
x = -60