(26 - 3 x ): 5 +71=75
5x+1 =125
câu 1:(26-3x):5+71=75
câu 2:5^x+1=125
câu 3:B={xϵN/30<x lớn hơn bằng 40}
câu 4:100-7.(5-x)=58
câu 1 : ( 26 - 3x ) : 5 + 71 = 75
( 26 - 3x ) : 5 = 4
26 - 3x =20
3x = 26 - 20
3x=6
x=6: 3
x=2
C4: 100 - 7( 5 - x) = 58
7( 5 -x ) = 100- 58
7( 5 - x) =42
5 - x = 42 : 7
5 - x = 6
x = -1
1. \(\left(26-3x\right):5+71=75\)
\(\left(26-3x\right):=75-71\)
\(\left(26-3x\right):5=4\)
\(26-3x=4.5\)
\(26-3x=20\)
\(3x=26-20\)
\(3x=6\)
\(x=6:3\)
\(x=2\)
2. \(5^{x+1}=125=5^3\)
\(x+1=3\Rightarrow x=2\)
3. B = {x ϵ N/30 < x < 40}
B = {31;32;33;34;35;36;37;38;39;40}
4. \(100-7\left(5-x\right)=58\)
\(100-35+7x=58\)
\(-7x=100-35-58=7\)
\(x=-7:7\)
\(x=-1\)
1.Tìm x: \(71\frac{47}{125}-\left(x-\frac{1}{5}\right)^3=71\frac{111}{125}\)
\(\frac{1}{2}.x+75\%.\left(x-2\right)=3\)
Tính :
C = (2/39 - 1/15 - 2/153)/(1/34 + 3/20 -3/26) × (1 + 2/71 - 5/121)/(65/121 - 26/71 -13)
Bài 6 . Tìm x biết: 1) 58 + 7x = 100 AI LM ĐC MÌNH CHO 20 XU
2) 101 +(36 – 4x) =105
3) 3x – 7 = 28
4) ( x – 12):12=12
5) x – 56 : 4= 16
6) (3.x-2 4 ).73=2.74
7) 71 – (33 + x) = 26
8) = 7 10) 4(x + 41) = 400
9) 45 – (x + 9):2 = 6
11) 2. (x + 7) – 25 = 13
13) 2(x- 51) = 2.23 + 20
15) 450 : (x – 19) = 50
17) 10 - (x – 3): 2 = 72 – 1 10
19) 2x + 2 – 2 x = 48
8) 140 : (x – 12) 5(x – 9) = 350
14) 2x – 49 = 5.32
16) 200 – (2x + 6) = 43
18) 135 – 5.(x + 4) = 35
20) (3x – 5)3 – 1 = 26
\(1,\Leftrightarrow7x=42\Leftrightarrow x=6\\ 2,\Leftrightarrow36-4x=4\Leftrightarrow4x=32\Leftrightarrow x=8\\ 3,\Leftrightarrow3x=35\Leftrightarrow x=\dfrac{35}{3}\\ 4,\Leftrightarrow x-12=144\Leftrightarrow x=156\\ 5,\Leftrightarrow x-14=16\Leftrightarrow x=30\\ 6,\Leftrightarrow3x-24=\dfrac{148}{73}\Leftrightarrow3x=\dfrac{1900}{73}\Leftrightarrow x=\dfrac{1900}{219}\\ 7,\Leftrightarrow33+x=45\Leftrightarrow x=12\\ 8,Sai.đề\\ 9,\Leftrightarrow\left(x+9\right):2=39\Leftrightarrow x+9=78\Leftrightarrow x=69\\ 11,\Leftrightarrow2\left(x+7\right)=38\Leftrightarrow x+7=19\Leftrightarrow x=12\\ 13,\Leftrightarrow2\left(x-51\right)=66\Leftrightarrow x-51=33\Leftrightarrow x=84\)
\(15,\Leftrightarrow x-19=9\Leftrightarrow x=28\\ 17,\Leftrightarrow\left(x-3\right):2=48\Leftrightarrow x-3=96\Leftrightarrow x=99\\ 19,\Leftrightarrow0x=46\Leftrightarrow x\in\varnothing\\ 8,Sai.đề\\ 14,\Leftrightarrow2x=209\Leftrightarrow x=\dfrac{209}{2}\\ 16,\Leftrightarrow2x+6=157\Leftrightarrow2x=151\Leftrightarrow x=\dfrac{151}{2}\\ 18,\Leftrightarrow5\left(x+4\right)=100\Leftrightarrow x+4=20\Leftrightarrow x=16\\ 20,\Leftrightarrow\left(3x-5\right)^3=27=3^3\Leftrightarrow3x-5=3\Leftrightarrow x=\dfrac{8}{3}\)
71+(26-3.x):5=75
71 + ( 26 - 3 . x ) ; 5 = 75
( 26 - 3x ) : 5 = 75 - 71
( 26 - 3x ) : 5 = 4
26 - 3x = 4.5
26 - 3x = 20
3x = 26 - 20
3x = 6
x = 6 : 3
x = 2
71+(26-3.x):5=75
71+(26-3x)=75.5=375
26-3x=375-71=304
3x=26-304=-278
x=\(\frac{-278}{3}\)
71 + (26 - 3 . x):5 = 75
26 -3 .x : 5 = 75-71
26 - 3 .x : 5 = 4
3 .x : 5 = 26 - 4
3 .x : 5 = 22
3 .x = 22 . 5
3.x = 110
x = ?
2/39 - 1/15- 2/153 phan 1/54+ 3/20- 3/26 chia cho 1+ 2/71 -5/121 phan 65/121- 26/71 -13
Bài 3: Tìm x e Z:
1) 71 – (33 + x)= 26
2) (x + 73) – 26 = 76
3) x - 7 = -5
4) -23 +x = - (- 25)
5) -5 < x ≤ 6
6) 140 : (x – 8) = 7
1, <=>33+x=45
<=> x = 12
Vậy x=12
2, <=>x+73 =102
<=> x =29
3,x=2
4, -23+x=25<=>x=2
6, x-8=20<=>x=28
26 x 5^x-1- 5^x-1=125
\(26\cdot5^{x-1}-5^{x-1}=125\)
\(\Rightarrow5^{^{x-1}}\cdot\left(26-1\right)=125\)
\(\Rightarrow5^{x-1}\cdot25=125\)
\(\Rightarrow5^{x-1}=\dfrac{125}{25}\)
\(\Rightarrow5^{x-1}=5\)
\(\Rightarrow x-1=1\)
\(\Rightarrow x=1+1\)
\(\Rightarrow x=2\)
\(\Leftrightarrow5^{x-1}\cdot\left(26-1\right)=125\)
=>\(5^{x-1}=5\)
=>x-1=1
=>x=2
\(\frac{\text{2/36 - 1/15 - 2/153}}{\text{1/34 + 3/20 - 3/26 }}:\frac{\text{1 + 2/71 - 5/121}}{\text{65/121 - 26/71 - 13 }}\)