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\(\text{720 : [41−(2x−5)] = 40720:[41−(2x−5)]=40}\)
\(\text{⇔41−(2x−5)=720:40}\)
\(\text{⇔ 41−2x+5=18}\)
\(\text{⇒ 46 −2x=18}\)
\(\text{⇔2x=28}\)
\(\text{⇔x=14}\)
720 : [ 41 - ( 2x-5)] = 2^3 .5
=> 720 :[ 41- (2x-5)] = 40
=> 41 - (2x-5) = 18
=> 2x -5 = 23
=> 2x = 28
=> x=14
9. (x + 28) = 0
x + 28 = 0: 9
x + 28 = 0
x = 0 – 28
x = -28
Vậy x = -28.
720:[41-(2x-5)]=23.5
720:[41-(2x-5)]=8.5
720:[41-(2x-5)]=40
41-(2x-5)=720:40
41-(2x-5)=18
2x-5=41-18
2x-5=23
2x=23+5
2x=28
x=28:2
x=14
Vậy x=14
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
c ( 3x2 -6 ) - 43 = 53
( 3x2 -6 ) - 43 = 125
3x2 -6=125+43
3x2 -6=168
3x2=168+6
3x2=174
x2=174:3
x2=58(đề sai)
d) 3x + 2x ( 23 . 5 - 32 . 4 ) + 52 = 44
3x + 2x ( 8 . 5 - 9 . 4 ) + 25 = 256
3x + 2x.4 + 25 = 256
3x + 2x.4=256-25
3x + 2x.4=231
(3+2).x.4=231
5x.4=231
5x=231:4
5x=57,75
x=57,75:5
x=11,55
e) 720 : [ 41 - ( 2x - 5 ) ] = 23 . 5
720 : [ 41 - ( 2x - 5 ) ] =40
41 - ( 2x - 5 )=720:40
41 - ( 2x - 5 )=18
2x - 5=41-18
2x - 5=23
2x=23+5
2x=28
x=28:2
x=14
m , Ta có : \(\left(1900-2.x\right):3-32=16\)
\(\Leftrightarrow\frac{1900-2.x}{35}-32=16\)( Nhân hai vế với 35 )
\(\Leftrightarrow1900-2.x-1120=560\)
\(\Leftrightarrow780-2.x=560\)
\(\Leftrightarrow-2.x=560-780\)
\(\Leftrightarrow\) \(-2.x=-220\)
\(\Rightarrow x=110\)
Vậy x = 110
n, Ta có : \(720:\left[41-\left(2.x-5\right)\right]=2^3.5\)
\(\Leftrightarrow720:\left(41-2.x+5\right)=8.5\)
\(\Leftrightarrow720:\left(46-2.x\right)=40\)
\(\Leftrightarrow\frac{720}{46-2.x}=40\)
\(\Leftrightarrow\frac{720}{2.\left(23-x\right)}=40\)
\(\Leftrightarrow\frac{360}{23-x}\)
\(\Leftrightarrow360=40.\left(23-x\right)\)
\(\Leftrightarrow9=23-x\)
\(\Leftrightarrow x=14\)
Vậy x = 14
720:[41-(2x-5)]=23.5
720:[41-(2x-5)]=8.5
720:[41-(2x-5)]=40
[41-(2x-5)]=720:40
[41-(2x-5)]=18
2x-5 = 41-18
2x-5= 23
2x = 23+5
2x = 28
x =28:2
x = 14