Tim x
A)2x.5:3=26.2.5.2
B)x.5.6:3=9990
C)85.4-x:5=339,4
D)86.56:x-23=665
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Tìm x thuoc z:
1) \(26-\left|x+9\right|=-13\)
\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)\)
\(\Leftrightarrow\left|x+9\right|=39\)
\(\Leftrightarrow\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=39-9=30\\x=-39-9=-48\end{matrix}\right.\)
Vậy: \(x\in\left\{30;-48\right\}\)
2) \(\left|x+7\right|-13=25\)
\(\Leftrightarrow\left|x+7\right|=25+13=38\)
\(\Leftrightarrow x+7\in\left\{38;-38\right\}\)
\(\Leftrightarrow x\in\left\{31;-45\right\}\)
Vậy:.................
tim x biet
\(1)123-3.\left(x+4\right)=23\)
\(\Leftrightarrow3\left(x+4\right)=123-23\)
\(\Leftrightarrow3\left(x+4\right)=100\)
\(\Leftrightarrow x+4=\frac{100}{3}\)
\(\Leftrightarrow x=\frac{100}{3}-4=\frac{100-12}{3}=\frac{88}{3}\)
Vậy:................
2) Tương tự
2346 : (25 + x) = 23
=> 25 + x = 2346 : 23 = 102
=> x = 102 - 25 = 77
Vậy x = 77
2(x-3) + 5(x+4) = 49
=> 2x - 6 + 5x + 20 = 49
=> 7x + (20 - 6) = 49
=> 7x + 14 = 49
=> 7x = 49 - 14 = 35
=> x = 35 : 7 = 5
Vậy x = 5
(2x-10)3 . 251007 = \(5^2.5^{2015}\)
\(\left(2x-10\right)^3.5^{2014}=5^{2014}.5^3\)
\(\left(2x-10\right)^3=5^3\)
2x - 10 = 5
=> 2x = 5 + 10 = 15
=> x = 15 2 = 7,5
Vậy x = 7,5
1. a. 2346:(25+x)=23
=> 25+x=2346:23
=> 25+x=102
=> x=102-25
=> x=77
b. 2(x-3)+5(x+4)=49
=> 2x-6+5x+20=49
=> 7x+14=49
=> 7x=49-14
=> 7x=35
=> x=35:7
=> x=5
c. (2x-10)3.251007=52.52015
=> (2x-10)3.(52)1007=52017
=> (2x-10)3.52014=52017
=> (2x-10)3=52017:52014
=> (2x-10)3=53
=> 2x-10=5
=> 2x=5+10
=> 2x=15
=> x=15:2
=> x=7,5
a: \(\Leftrightarrow2^x=1024\cdot3+1024\cdot7776+7776\cdot5\)
\(\Leftrightarrow2^x=8004576\)
hay \(x\in\varnothing\)
b: \(\Leftrightarrow x\left(x+3\right)^{100}-\left(x+3\right)^{100}=0\)
\(\Leftrightarrow\left(x+3\right)^{100}\left(x-1\right)=0\)
=>x=-3 hoặc x=1
a: =>x+7/4=6:2/3=9
=>x=29/4
b: =>x:5/3=7/5
=>x=7/5*5/3=7/3
c:=>x+1/6=5/3
=>x=10/6-1/6=3/2
d: =>x+4/5=4/5+3/7+3/5
=>x=3/7+3/5=36/35
e: =>x/35=4/5-5/7=3/35
=>x=3
f: =>13/28+x=1/2
=>x=1/28
g: =>1/3-x=1/9
=>x=2/9
a) 3x(4x-3)-2x(5-6x)=0
\(\Leftrightarrow12x^2-9x-10x+12x^2=0\)
\(\Leftrightarrow24x^2-19x=0\)
\(\Leftrightarrow x\left(24x-19\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\24x-19=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\24x=19\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{19}{24}\end{matrix}\right.\)
Vậy x=0 hoặc x=\(\dfrac{19}{24}\)
D) 86.56:x-23=665
4816:x=665+23
4816:x=688
x=4816:688
x=7
C) 85.4-x:5=339,4
340-x:5=339,4
-x:5=339,4-340
-x:5=-0,6
x:5=0,6
x=0,6.5
x=3