tìm x,biết 5x-4/5=x+13/15
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a) 5.2² + (x + 3) = 5²
5.4 + x + 3 = 25
20 + x + 3 = 25
x + 23 = 25
x = 25 - 23
x = 2
b) 2³ + (x - 3²) = 5³ - 4³
8 + (x - 9) = 125 - 64
8 + x - 9 = 61
x - 1 = 61
x = 61 + 1
x = 62
c) 4.(x - 5) - 2³ = 2⁴.3
4x - 20 - 8 = 16.3
4x - 28 = 48
4x = 48 + 28
4x = 76
x = 76 : 4
x = 19
d) 5.(x + 7) - 10 = 2³.5
5x + 35 - 10 = 8.5
5x + 25 = 40
5x = 40 - 25
5x = 15
x = 15 : 5
x = 3
e) 7² - 7.(13 - x) = 14
49 - 91 + 7x = 14
7x - 42 = 14
7x = 14 + 42
7x = 56
x = 56 : 7
x = 8
a) \(5\cdot2^2+\left(x+3\right)=5^2\)
\(\Rightarrow x+3=5^2-5\cdot2^2\)
\(\Rightarrow x+3=25-5\cdot4\)
\(\Rightarrow x+3=5\)
\(\Rightarrow x=5-3\)
\(\Rightarrow x=2\)
b) \(2^3+\left(x-3^2\right)=5^3-4^3\)
\(\Rightarrow8+\left(x-9\right)=125-64\)
\(\Rightarrow8+x-9=61\)
\(\Rightarrow x-1=61\)
\(\Rightarrow x=61+1\)
\(\Rightarrow x=62\)
c) \(4\left(x-5\right)-2^3=2^4\cdot3\)
\(\Rightarrow4\left(x-5\right)=2^4\cdot3+2^3\)
\(\Rightarrow4\cdot\left(x-5\right)=16\cdot3+8\)
\(\Rightarrow4\cdot\left(x-5\right)=56\)
\(\Rightarrow x-5=56:4\)
\(\Rightarrow x-5=14\)
\(\Rightarrow x=19\)
d) \(5\left(x+7\right)-10=2^3\cdot5\)
\(\Rightarrow5\left(x+7\right)=8\cdot5+10\)
\(\Rightarrow5\left(x+7\right)=40+10\)
\(\Rightarrow5\left(x+7\right)=50\)
\(\Rightarrow x+7=10\)
\(\Rightarrow x=10-7\)
\(\Rightarrow x=3\)
e) \(7^2-7\left(13-x\right)=14\)
\(\Rightarrow7\left(13-x\right)=7^2-14\)
\(\Rightarrow7\left(13-x\right)=49-14\)
\(\Rightarrow7\left(13-x\right)=35\)
\(\Rightarrow13-x=5\)
\(\Rightarrow x=13-5\)
\(\Rightarrow x=8\)
f) \(5x-5^2=10\)
\(\Rightarrow5x=10+5^2\)
\(\Rightarrow5x=10+25\)
\(\Rightarrow5x=35\)
\(\Rightarrow x=\dfrac{35}{5}\)
\(\Rightarrow x=7\)
g) \(9x-2\cdot3^2=3^4\)
\(\Rightarrow9x=3^4+2\cdot3^2\)
\(\Rightarrow9x=81+2\cdot9\)
\(\Rightarrow9x=99\)
\(\Rightarrow x=\dfrac{99}{9}\)
\(\Rightarrow x=11\)
h) \(10x+2^2\cdot5=10^2\)
\(\Rightarrow10x=10^2-2^2\cdot5\)
\(\Rightarrow10x=100-4\cdot5\)
\(\Rightarrow10x=80\)
\(\Rightarrow x=\dfrac{80}{10}\)
\(\Rightarrow x=8\)
i) \(125-5\left(4+x\right)=15\)
\(\Rightarrow5\left(4+x\right)=125-5\)
\(\Rightarrow5\left(4+x\right)=120\)
\(\Rightarrow4+x=\dfrac{120}{5}\)
\(\Rightarrow4+x=24\)
\(\Rightarrow x=24-4\)
\(\Rightarrow x=20\)
j) \(2^6+\left(5+x\right)=3^4\)
\(\Rightarrow5+x=3^4-2^6\)
\(\Rightarrow5+x=81-64\)
\(\Rightarrow5+x=17\)
\(\Rightarrow x=17-5\)
\(\Rightarrow x=12\)
\(1\)) \(5-\left(10-x\right)=7\)
\(10-x=5-7\)
\(10-x=-2\)
\(x=10-\left(-2\right)\)
\(x=12\)
\(2\)) \(-32-\left(x-5\right)=0\)
\(x-5=-32-0\)
\(x-5=-32\)
\(x=-32+5\)
\(x=-27\)
a)
<=> 10x - 35 + 16x - 10 = 5
<=> 10x + 16x = 5 + 35 + 10
<=> 26x = 50
<=> x = 50/26 = 25/13
\(\text{1) -5x - (-3)= 13}\)
\(\Rightarrow-5x=10\)
\(x=10:-5\)
\(x=-2\)
\(\text{2) |x-3| - 7= 13}\)
\(\Rightarrow|x-3|=20\)
\(\Rightarrow\orbr{\begin{cases}x-3=20\\x-3=-20\end{cases}\Leftrightarrow\orbr{\begin{cases}x=23\\x=-17\end{cases}}}\)
\(\text{3) 17- (43 - |x|)= 45}\)
\(\Rightarrow43-|x|=-28\)
\(|x|=71\)
\(\Rightarrow\orbr{\begin{cases}x=71\\x=-71\end{cases}}\)
\(\text{5) (x-2).(x+15)= 0}\)
\(\Rightarrow\orbr{\begin{cases}x-2=0\\x+15=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=2\\x=-15\end{cases}}}\)
4,\(\text{4) (x-3).(x-5) < 0}\)\(\left(x-3\right).\left(x-5\right)< 0\)
\(\Rightarrow\left(x-3\right)\)và \(\left(x-5\right)\)trái dấu
Mà \(\left(x-3\right)>\left(x-5\right)\Rightarrow\left(x-3\right)>0\)và \(\left(x-5\right)< 0\)
\(+,x-3>0\Rightarrow x>3\)
\(+,x-5< 0\Rightarrow x< 5\)
\(\Rightarrow3< x< 5\)
\(\)Mà \(x\in Z\)
\(\Rightarrow x=4\)
học tốt
1<=>-5x+3=13
<=>-5x=10
<=>x=-2
2<=>|x-3|=20
th1:x-3=20
<=>x=23
th2:x-3=-20
<=>x=-17
3,<=>17-43+|x|=45
<=>|x|=71
th1:x=71
th2:x=-71
4<=>x-3<0 x-5>0
<=>x<3 x>5(loại vì ko có số naod vừa lớn hơn 5 và nhỏ hơn 3)
<=>x-3>0 x-5<0
<=>x>3 x<5
=>3<x<5
5,<=>x-2=0 x+15=0
<=>x=2 x=-15
https://www.youtube.com/channel/UCb2H-q6FmW61PgcsL1OGPfw ủng hộ bạn t:))
\(-12\left(x-5\right)+7\left(3-x\right)=15\)
\(\Rightarrow-12x+60+21-7x=15\)
\(\Rightarrow-12x-7x=15-21-60\)
\(\Rightarrow-19x=-66\)
\(\Rightarrow x=\frac{66}{19}\)
\(\left|2x-5\right|=12\)
\(\Leftrightarrow\orbr{\begin{cases}2x-5=12\\2x-5=-12\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x=17\\2x=-7\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{17}{2}\left(t/m\right)\\x=-\frac{7}{2}\left(t/m\right)\end{cases}}\)
\(5x-\dfrac{4}{5}=x+\dfrac{13}{15}\)
\(\Rightarrow5x-x=\dfrac{13}{15}+\dfrac{4}{5}\)
\(\Rightarrow4x=\dfrac{13}{15}+\dfrac{12}{15}\)
\(\Rightarrow4x=\dfrac{25}{15}\)
\(\Rightarrow4x=\dfrac{5}{3}\)
\(\Rightarrow x=\dfrac{5}{3}:4\)
\(\Rightarrow x=\dfrac{5}{12}\)
5x-4/5=x+13/15
<=>5x-x=13/15+4/5
<=>4x=5/3
<=>x=5/12
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