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a) \(x-\frac{4}{5}=\frac{5}{7}\)
\(x=\frac{5}{7}+\frac{4}{5}=\frac{53}{35}\)
b) \(5x=-\frac{1}{5}\)
\(x=-\frac{1}{5}:5=-\frac{1}{25}\)
c) \(\frac{5}{3}-x=7+\frac{4}{5}\)
\(\frac{5}{3}-x=\frac{39}{5}\)
\(x=\frac{5}{3}-\frac{39}{5}=-\frac{92}{15}\)
d) \(-\frac{5}{11}+2x=\frac{7}{22}\)
\(2x=\frac{7}{22}+\frac{5}{11}\)
\(2x=\frac{17}{22}\)
\(x=\frac{17}{22}:2\)
\(x=\frac{17}{44}\)
\(x=-\frac{1}{5}:5\)
NÈ BẠN!!!
a) \(x-\frac{4}{5}=\frac{5}{7}\)
\(x=\frac{5}{7}+\frac{4}{5}=\frac{25}{35}+\frac{28}{35}=\frac{53}{35}\)
b) \(5x=-\frac{1}{5}+\frac{11}{5}\)
\(5x=2\)
\(x=\frac{2}{5}\)
c)\(\frac{5}{3}-x=7\)
\(x=\frac{5}{3}-7=\frac{5}{3}-\frac{21}{3}=-\frac{16}{3}\)
d) \(-\frac{5}{11}+2x=\frac{7}{22}\)
\(2x=\frac{7}{22}-\frac{-5}{11}=\frac{7}{22}-\frac{-10}{22}=\frac{17}{22}\)
\(x=\frac{17}{22}:2=\frac{17}{22}\cdot\frac{1}{2}=\frac{17}{44}\)
K CHO MÌNH NHA!!!
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\(F=\left|x\right|+\left|x+2\right|=\left|-x\right|+\left|x+2\right|\ge\left|-x+x+2\right|=2\)(Áp dụng bất đẳng thức \(\left|a\right|+\left|b\right|\ge\left|a+b\right|\))Dấu "=" xảy ra \(\Leftrightarrow-x\left(x+2\right)\ge0\)
\(\Leftrightarrow\orbr{\begin{cases}\hept{\begin{cases}-x\ge0\\x+2\ge0\end{cases}}\\\hept{\begin{cases}-x\le0\\x+2\le0\end{cases}}\end{cases}}\Leftrightarrow\orbr{\begin{cases}\hept{\begin{cases}x\le0\\x\ge-2\end{cases}\Rightarrow x=0;-1;-2}\\\hept{\begin{cases}x\ge0\\x\le-2\end{cases}\Rightarrow x\in\varnothing}\end{cases}}\)
Vậy x = 0;-1;-2
cái chỗ giải -x(x+2) >=0 bạn tự giải làm 2 trường hợp: (-x>=0 và x+2>=0) hoặc (-x<=0 và x+2<=0)
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\(M=1+\dfrac{1}{5}+\dfrac{3}{35}+...+\dfrac{3}{9999}\\ =\dfrac{3}{3}+\dfrac{3}{15}+\dfrac{3}{35}+...+\dfrac{3}{9999}\\ =\dfrac{3}{2}\left(\dfrac{2}{1\cdot3}+\dfrac{2}{3\cdot5}+...+\dfrac{2}{99\cdot101}\right)\\ =\dfrac{3}{2}\left(1-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+...+\dfrac{1}{99}-\dfrac{1}{101}\right)\\ =\dfrac{3}{2}\left(1-\dfrac{1}{101}\right)=\dfrac{3}{2}\cdot\dfrac{100}{101}=\dfrac{150}{101}\)
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-x-20-(8-2x)=(-12-3)
-x-20-8+2x=-15
x-28=-15
x=13
Vậy x=13
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài làm
| -17 | + 27
= 17 + 27
= 44
# Chúc bạn học tốt #
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7x - 33 = 27 : 2
7x - 27 = 26
7x - 27 = 64
7x = 64 + 27
7x = 91
x = 91 : 7
x = 13
Hok tốt nhé :)
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a) 3(x + 5) - 8 = x + 17
=> 3x + 15 - 8 = x + 17
=> 3x + 7 = x + 17
=> 3x - x = 17 - 7
=> 2x = 10
=> x = 10 : 2
=> x = 5
b) 5(x + 3) - 10 = 2x - 19
=> 5x + 15 - 10 = 2x - 19
=> 5x + 5 = 2x - 19
=> 5x - 2x = -19 - 5
=> 3x = -24
=> x = -24 : 3
=> x = -8
a. 3x+15-8=x+17
3x-x=17-15+8
2x=10
x=5
b.5x+15-10=2x-19
5x+5=2x-19
5x-2x=-19-5
3x=-24
x=-8
thank
( 7 . x - 11)\(^3\)=2\(^5\). 2\(^2\)+ 200
( 7 . x - 11)\(^3\)=32 . 4 + 200
( 7. x - 11)\(^3\)=328
( 7 . x - 1331) = 328
7 . x = 328 + 1331
7.x = 1659
x = 1659 : 7
x = 237
(7x-11)3=25.22+200
(7x-11)3=27+200
(7x-11)3=128+200
(7x-11)3=328
vô lí vì \(328\ne?^?\)được
vậy x\(\notin\varnothing\)