a) (2x -4)3 = 8 b) 720 : [41 -(2x-5)]=23. 5
1.tìm x
a,128-3.(x=4)=23 b,[(4x =28).3=55]:5=35
c,(12x-4^3).8^3=4.8^4 d,720 :[41-(2x-5)]=263.5
\(a,128-3.\left(x+4\right)=23\\ \Rightarrow3.\left(x+4\right)=105\\ \Rightarrow x+4=35\\ \Rightarrow x=31\\ b,\left[\left(4x+28\right).3+55\right]:5=35\\ \Rightarrow\left(4x+28\right).3+55=175\\ \Rightarrow4x+28.3=120\\ \Rightarrow4x+28=60\\ \Rightarrow4x=32\\ \Rightarrow x=8.\)
c) \(\left(12x-4^3\right).8^3=4.8^4\)
\(12x-64=4.8^4:8^3\)
\(12x-64=32\)
\(12x=32+64\)
\(12x=96\)
\(x=\dfrac{96}{12}\)
\(x=8\)
d) \(720:\left[41-\left(2x-5\right)\right]:5=35\)
\(720:\left(41-2x+5\right):5=35\)
\(720:\left(46-2x\right)=35.5\)
\(720:\left(46-2x\right)=175\)
\(46-2x=720:175\)
\(46-2x=\dfrac{144}{35}\)
\(2x=46-\dfrac{144}{35}\)
\(2x=\dfrac{1466}{35}\)
\(x=\dfrac{1466}{35}:2\)
\(x=\dfrac{733}{35}\)
tim x
a, ( 2x - 4 ) ^ 3 = 8
b, 720 / [ 41 - ( 2x - 5 ) ] = 2^3 * 5
(2x - 4)3 = 8
(2x - 4)3 = 23
2x - 4 = 2
2x = 2 + 4
2x = 6
x = 6 : 2
x = 3
\(\frac{720}{41-\left(2x-5\right)}=2^3\times5\)
\(\frac{720}{41-2x+5}=8\times5\)
\(46-2x=\frac{720}{40}\)
\(2x=46-18\)
2x = 28
x = 28 : 2
x = 14
a)2x – 12.4 = 28
b)128-3(x +4)= 23
c) 20 + 8.(x + 3) = 52 .4
d) (12x -4 3 ).83= 4.84
e) 720: [41-(2x-5)]=23 .5
f) (2x- 4)(x – 3) = 0
g) (2x +1)3= 5.25
h) 2 x . 4 = 128
i) 5x-2 = 1
k)2x + 2x + 3= 144
giúp me được ko
Bài 2. Tìm x biết:
a, 128 - 3(x + 4) = 23 d, 720 : [41 - (2x - 5)] = 2 3 .5
b, [(4x + 28).3 + 55] : 5 = 35 e, 123 – 5.( x + 4 ) = 38
c, (12x - 4 3 ).8 3 = 4.8 4 g, ( 3x – 2 4 ) .7 3 = 2.7 4
a,
128-3x-12=23
3x=128-12-23
3x=93
x=93:3
= 31
b,
(12x+84+55):5=35
12x+84+55=35.5
12x+84+55=175
12x=175-55-84
12x=36
x=36:12
x=3
Tìm số tự nhiên x biết:
a, 128 – 3(x+4) = 23
b, 12 x - 4 3 . 8 3 = 4 . 8 4
c, [(4x+28).3+55]:5 = 35
d, 720:[41 – (2x – 5)] = 2 3 . 5
a, 128 – 3(x+4) = 23
b, 12 x - 4 3 . 8 3 = 4 . 8 4
c, [(4x+28).3+55]:5 = 35
d, 720:[41 – (2x – 5)] = 2 3 . 5
tìm x
128 - 3 . ( x + 4 ) = 23
[ ( 4x +28 ) . 3 + 55 ] : 5 = 35
( 12x - 4^3 ) . 8^3 = 4.8^4
720 : [ 41 - ( 2x - 5 )] = 2^3 . 5
128-3.(x+4) =23
3.(x+4) =128-23
3.(x+4) = 105
x+4 =105:3
x+4 =35
x = 35-4
x=31
Tìm x biết:
a, 2 3 x + 5 2 x = 2 5 2 + 2 3 - 33
b, 260 : x + 4 = 5 2 3 + 5 - 3 3 2 + 2 2
c, 720 : [ 41 - 2 x - 5 ] = 2 3 . 5
d, 3 2 - 2 x - 12 + 35 = 5 2 + 279 : 3 2
a, 2 3 x + 5 2 x = 2 5 2 + 2 3 - 33
8x+25x = 33
33x = 33
x = 1
b, 260 : x + 4 = 5 2 3 + 5 - 3 3 2 + 2 2
260:(x+4) = 5.13–3.13
x+4 = 260:26
x+4 = 10
x = 6
c, 720 : [ 41 - 2 x - 5 ] = 2 3 . 5
41–(2x–5) = 720:40
2x–5 = 41–18
2x = 28
x = 14
d, 3 2 - 2 x - 12 + 35 = 5 2 + 279 : 3 2
7(x–12)+35 = 56
7(x–12) = 21
x–12 = 3
x = 15
tìm x biết
a) 120 - 3 ( x + 4 ) = 23
b) [ ( 4x + 28 ) . 3 + 55 ] : 5 = 35
c) ( 12x - 43 ) . 83 = 4 . 84
d) 720 : [ 41 - ( 2x - 5 ) ] = 23 . 5
giúp mk nha mk cần gấp
a)120-3(x+4)=23
=>3(x+4)=120-23
=>3(x+4)=97
=>x+4=97:3
=>x+4=\(\frac{97}{3}\)
=>x=\(\frac{97}{3}\)-4
=>x=\(\frac{85}{3}\)
Vậy x=\(\frac{85}{3}\)
b)[(4x+28).3+55]:5=35
=>(4x+28).3+55=35.5
=>(4x+28).3+55=175
=>(4x+28).3=175-55
=>(4x+28).3=120
=>4x+28=120:3
=>4x+28=40
=>4x=40-28
=>4x=12
=>x=12:4
=>x=3
Vậyx= 3
c)\((12x-4^3).8^3=4.8^4\)
=>\(12x-64=4.8^4:8^3\)
=>12x-64=4.8
=>12x-64=32
=>12x=96
=>x=96:12
=>x=8
Vậy x=8
d)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
Vậy x=14
a, 120 - 3 [ x+4]=23
3 [x+4]= 120-23 = 97
3x = 97-4
3x= 93
x= 93:3
x=31
em bt làm mỗi bài này thui mà ko bt đúng ko
a) 120 - 3(x + 4) = 23
=> 3(x + 4) = 120 - 23 = 97
=> x + 4 = 97 : 3
=> x + 4 = 97/3
=> x = 97/3 - 4 = 85/3
b) [(4x + 28) . 3 + 55] : 5 = 35
=> [(4x + 28) . 3 + 55] = 175
=> (4x + 28).3 + 55 = 175
=> (4x + 28).3 = 120
=> 4x + 28 = 40
=> 4x = 12
=> x = 3
c) (12x - 43).83 = 4.84
=> (12x - 43) = \(\frac{4\cdot8^4}{8^3}=4\cdot8=32\)
=> 12x - 64 = 32
=> 12x = 96
=> x = 96 : 12 = 8
d) Tương tự
2x+23=37:34
[(4x+28).3+55]:5=35
17-(3x+9)=2-(-3+x)
(12x-43).83=4.84
720:[41-(2x-5)]=23.5
128-3.(x+4)=23
(1)\(2x+23=3^7\div3^4\)
\(2x+23=3^3\)
\(2.x=27-23=4\)
\(x=4\div2\)
\(x=2\)
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