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NN
13 tháng 12 2022
a.1+3+5+7+...+2x+1=225
[(2x+1-1):2+1]x(2x+1+1):2=225
(x+1)x(2x+2):2=225
(x+1)x(x+1)=225
(x+1)2=225
(x+1)2=152
x+1=15
x=14
_______________
b. 130-[5.(9-x)+43]=47
5.(9-x)+43=83
5.(9-x)=40
9-x=8
x=1
_______________
c.16x<324
24x<220
=>x∈{0;1;2;3;4}
13 tháng 12 2022
a: =>(x+1)^2=225
=>x+1=15
=>x=14
b: =>[5*(9-x)+43]=130-47=83
=>5(9-x)=40
=>9-x=8
=>x=1
c: =>2^4x<2^20
=>4x<20
=>0<x<5
8 tháng 8 2023
4. ( x - 250 ) : 6 = 64 - 12
( x- 250 ) : 6 = 52
x - 250 = 312
x = 562
5. 10x = 1030
=> x = 103
6. 30x = 120
x = 4
7. \(x=2023\)
\(8.165-\left(35:x+3\right).19=13\)
\(\left(35:x+3\right).19=152\)
\(35:x+3=8\)
\(35:x=5\)
\(x=7\)
8 tháng 8 2023
4) \(\left(x-250\right)\div6=4^3-2^2\times3\)
\(\left(x-250\right)\div6=64-4\times3\)
\(\left(x-250\right)\div6=64-12=52\)
\(x-250=52\times6=312\)
\(x=312+250\)
\(x=562\)
5) \(2x+3x+5x=1030\)
\(x\left(2+3+5\right)=1030\)
\(10x=1030\)
\(x=1030\div10\)
\(x=103\)
6) \(15x-35x+50x=120\)
\(x\left(15-35+50\right)=120\)
\(30x=120\)
\(x=120\div30\)
\(x=4\)
7) \(\dfrac{1}{2}x+\dfrac{1}{6}x+\dfrac{1}{3}x=2023\)
\(x\left(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{6}\right)=2023\)
\(x\times1=2023\)
\(x=2023\)
8) \(165-\left(35\div x+3\right)\times19=13\)
\(\left(35\div x+3\right)\times19=165-13\)
\(\left(35\div x+3\right)\times19=152\)
\(35\div x+3=152\div19=8\)
\(35\div x=8-3=5\)
\(x=35\div5\)
\(x=7\)
MT
1
T
1 tháng 5 2019
a, |3x - 6| + 4x + 3 = 12
|3x - 6| = 12 - 3 - 4x
|3x - 6| = 9 - 4x
TH1: 3x - 6 = 9 - 4x ⇔ 3x + 4x = 9 + 6 ⇔ 7x = 15 ⇔ x = 15/7
TH2: 3x - 6 = 4x - 9 ⇔ 3x - 4x = -9 + 6 ⇔ -x = -3 ⇔ x = 3.
b, |6x - 12| + 3x - 1 = 43
|6x - 12| = 43 + 1 - 3x
|6x - 12| = 44 - 3x
TH1: 6x - 12 = 44 - 3x ⇔ 6x + 3x = 44 + 12 ⇔ 9x = 56 ⇔ x = 6.
TH2: 6x - 12 = 3x - 44 ⇔ 6x - 3x = -44 + 12 ⇔ 3x = -32 ⇔ x = -32/3.
c, |8 - 4x| + 7x - 5 = 16 - 2x
|8 - 4x| = (16 + 5) + (-2x - 7x)
|8 - 4x| = 21 - 9x
TH1: 8 - 4x = 21 - 9x ⇔ -4x + 9x = 21 - 8 ⇔ 5x = 13 ⇔ x = 13/5
TH2: 8 - 4x = 9x - 21 ⇔ -4x - 9x = -21 - 8 ⇔ -15x = -29 ⇔ x = 29/15
KL
2
17 tháng 1 2021
2: Tìm x
a) Ta có: x+25=40
nên x=40-25=15
Vậy: x=15
b) Ta có: 198-(x+4)=120
\(\Leftrightarrow x+4=198-120=78\)
hay x=78-4=74
Vậy: x=74
c) Ta có: \(\left(2x-7\right)\cdot3=125\)
\(\Leftrightarrow2x-7=\dfrac{125}{3}\)
\(\Leftrightarrow2x=\dfrac{125}{3}+7=\dfrac{125}{3}+\dfrac{21}{3}=\dfrac{146}{3}\)
\(\Leftrightarrow x=\dfrac{146}{3}:2=\dfrac{146}{6}=\dfrac{73}{3}\)
Vậy: \(x=\dfrac{73}{3}\)
d) Ta có: \(x+16⋮x+1\)
\(\Leftrightarrow x+1+15⋮x+1\)
mà \(x+1⋮x+1\)
nên \(15⋮x+1\)
\(\Leftrightarrow x+1\inƯ\left(15\right)\)
\(\Leftrightarrow x+1\in\left\{1;-1;3;-3;5;-5;15;-15\right\}\)
hay \(x\in\left\{0;-2;2;-4;4;-6;14;-16\right\}\)
Vậy: \(x\in\left\{0;-2;2;-4;4;-6;14;-16\right\}\)
17 tháng 1 2021
\(a,x+25=40\\ \Rightarrow x=40-25\\ \Rightarrow x=15\\ b,198-\left(x+4\right)=120\\ \Rightarrow-\left(x+4\right)=120-198\\ \Rightarrow-\left(x+4\right)=-78\\ \Rightarrow x+4=78\\ \Rightarrow x=78-4\\ \Rightarrow x=74\\ c,\left(2x-7\right).3=125\\ \Rightarrow2x-7=\dfrac{125}{3}\\ \Rightarrow2x=\dfrac{125}{3}+7\\ \Rightarrow2x=\dfrac{146}{3}\\ \Rightarrow x=\dfrac{146}{3}:2\Rightarrow x=\dfrac{73}{3}\\ d,\left(x+16\right)⋮\left(x+1\right)\\ \Rightarrow\left[\left(x+1\right)+15\right]⋮\left(x+1\right)\\ mà:\left(x+1\right)⋮\left(x+1\right)\\ \Rightarrow15⋮\left(x+1\right)\\ \Rightarrow\left(x+1\right)\inƯ\left(15\right)\\ \Rightarrow\left(x+1\right)\in\left\{-15;-1;1;15\right\}\\ \Rightarrow x\in\left\{-16;-2;0;14\right\}\)
Tự kết luận nhé bạn
9 tháng 11 2018
\(2.3^x=6.27^4\\ =>3^x=3.\left(3^3\right)^4\\ =>3^x=3^{13}\\ =>x=13\)
9 tháng 11 2018
2.3x=6.274
2.3x=2.3.3.3.34
2.3x=2.(34)4
2.3x=2.316
=> x = 16
mik ko chắc đâu nhưng có lẽ đúng
27 tháng 3 2020
a,-2x -(x-17)=34-(-x+25)
-2x-x+17=34+x-25
-3x+17=9+x
-3x-x=9-17
-4x=-8
-->4x=8
x=8:4
x=2
Vậy x=2
b,17-(16x-37)=2x+43
17-16x+37=2x+43
20-16x=2x+43
-16x-2x=43-20
-18x=23
x=23:(-18)
x=23/-18
Mà x là số nguyên nên --> x thuộc tập rỗng
c,-2x-3.(x-17)=34-2(-x+25)
-2x-3x+51=34-2.(-x)-25
-5x+51=9-(-2).x
-5x+(-2).x=9-51
-7x=-42
7x=42
x=42:7
x=6
Vậy x=6
H9
HT.Phong (9A5)
CTVHS
6 tháng 10 2023
Bài 1:
a) \(4^{x+2}+4^x=68\)
\(\Rightarrow4^x\cdot\left(4^2+1\right)=68\)
\(\Rightarrow4^x\cdot17=68\)
\(\Rightarrow4^x=\dfrac{68}{17}\)
\(\Rightarrow4^x=4\)
\(\Rightarrow4^x=4^1\)
\(\Rightarrow x=1\)
b) \(5\cdot2^{x+4}-3\cdot2^x=308\)
\(\Rightarrow2^x\cdot\left(5\cdot2^4-3\right)=308\)
\(\Rightarrow2^x\cdot\left(5\cdot16-3\right)=308\)
\(\Rightarrow2^x\cdot77=308\)
\(\Rightarrow2^x=\dfrac{308}{77}\)
\(\Rightarrow2^x=4\)
\(\Rightarrow2^x=2^2\)
\(\Rightarrow x=2\)
c) \(4\cdot3^{x+1}+7\cdot3^x=513\)
\(\Rightarrow3^x\cdot\left(4\cdot3+7\right)=513\)
\(\Rightarrow3^x\cdot19=513\)
\(\Rightarrow3^x=\dfrac{513}{19}\)
\(\Rightarrow3^x=27\)
\(\Rightarrow3^x=3^3\)
\(\Rightarrow x=3\)
d) \(5^{x+4}-5^x=3120\)
\(\Rightarrow5^x\cdot\left(5^4-1\right)=3120\)
\(\Rightarrow5^x\cdot\left(625-1\right)=3120\)
\(\Rightarrow5^x\cdot624=3120\)
\(\Rightarrow5^x\cdot\dfrac{3120}{624}\)
\(\Rightarrow5^x=5\)
\(\Rightarrow5^x=5^1\)
\(\Rightarrow x=1\)
f) \(3\cdot4^{2x+1}-16^x=2816\)
\(\Rightarrow3\cdot4^{2x+1}-\left(4^2\right)^x=2816\)
\(\Rightarrow3\cdot4^{2x+1}-4^{2x}=2816\)
\(\Rightarrow4^{2x}\cdot\left(3\cdot4-1\right)=2816\)
\(\Rightarrow4^{2x}\cdot11=2816\)
\(\Rightarrow4^{2x}=\dfrac{2816}{11}\)
\(\Rightarrow4^{2x}=256\)
\(\Rightarrow\left(2^2\right)^{2x}=2^8\)
\(\Rightarrow2^{4x}=2^8\)
\(\Rightarrow4x=8\)
\(\Rightarrow x=2\)
Bài 2:
\(2^x+124=5^y\)
\(\Rightarrow5^y-2^x=124\)
\(\Rightarrow5^y-2^x=125-1\)
\(\Rightarrow\left\{{}\begin{matrix}5^y=125\\2^x=1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}5^y=5^3\\2^x=2^0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}y=3\\x=0\end{matrix}\right.\)
Vậy: ....
H9
HT.Phong (9A5)
CTVHS
19 tháng 7 2023
Bài 6:
\(21,251+6,058+0,749+1,042\)
\(=\left(21,251+0,749\right)+\left(6,058+1,042\right)\)
\(=22+7,1\)
\(=29,1\)
___________________
\(1,53+5,309+12,47+5,691\)
\(=\left(1,53+12,47\right)+\left(5,309+5,691\right)\)
\(=14+11\)
\(=25\)
22 tháng 7 2023
5:
a: =>x/17=5/17
=>x=5
b; =>6+x=7/11*33=21
=>x=15
c: \(\dfrac{12+x}{43-x}=\dfrac{2}{3}\)
=>3x+36=86-2x
=>5x=50
=>x=10
d: \(\dfrac{x}{5}< \dfrac{3}{7}\)
=>x<3/7*5
=>x<15/7
f: 15/26+x/16=46/52
=>x/16=23/26-15/26=8/26=4/13
=>x=4/13*16=64/13
N
7 tháng 6 2017
x+2-3.4:5=2+4-5.2x
<=> x+2-12/5 = 6 - 10x
<=> 11x =6 - 2 + 12/5
<=> 11x = 32/5
<=> x = 32/55
k mik nha. tks bạn
7 tháng 6 2017
\(x+2-3.4:5=2+4-5.2x\)
=) \(x+2-\frac{12}{5}=6-10x\)
=) \(x+10x-\frac{12}{5}=6-2\)(CHUYỂN VẾ)
=) \(11x-\frac{12}{5}=4\)
=) \(11x=4+\frac{12}{5}=\frac{32}{5}\)
=) \(x=\frac{32}{5}:11=\frac{32}{55}\)
\(a,5x+4^3:16=49\)
\(5x+4=49\)
\(\Rightarrow5x=45\)
\(\Rightarrow x=9\)
\(b,2^x+5.2^x=6.2^7\)
\(2^x\left(1+5\right)=6.2^7\)
\(2^x.6=6.2^7\)
\(\Rightarrow x=7\)
a)\(5.x+4^3\div16=49\)
\(\Leftrightarrow5x+4^3\div4^2=49\)
\(\Leftrightarrow5x+4=49\)
\(\Leftrightarrow5x=45\Rightarrow x=9\)
Vậy x= 9
b)\(2^x+5.2^x=6.2^7\)
\(2^x\left(1+5\right)=6.2^7\)
\(2^x.6=6.2^7\Rightarrow2^x=2^7\Rightarrow x=7\)
Vậy x=7