3^x + 3^x+1 + 3^x+2 = 3159
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3x+3x-1+3x-2=3159
Tìm x,mình tick cho
Ta có :
\(3^x+3^{x-1}+3^{x-2}=3159\)
\(\Leftrightarrow\)\(3^x+3^x:3+3^x+3^2=3159\)
\(\Leftrightarrow\)\(3^x+3^x.\frac{1}{3}+3^x.\frac{1}{3^2}=3159\)
\(\Leftrightarrow\)\(3^x\left(1+\frac{1}{3}+\frac{1}{3^2}\right)=3159\)
\(\Leftrightarrow\)\(3^x.\frac{13}{9}=3159\)
\(\Leftrightarrow\)\(3^x=3159:\frac{13}{9}\)
\(\Leftrightarrow\)\(3^x=3159.\frac{9}{13}\)
\(\Leftrightarrow\)\(3^x=2187\)
\(\Leftrightarrow\)\(3^x=3^7\)
\(\Leftrightarrow\)\(x=7\)
Vậy \(x=7\)
Chúc bạn học tốt ~
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\(\Rightarrow3^x+3^{x-1}+3^{x-2}=3159\\ \Rightarrow3^{\left(x+x+x\right)\left(1-2-1\right)}\\ \Rightarrow3^{x-2}\\ \)
mà ????
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Tìm x
a. | x + 4| + 45 = 245
b. 3x+1 + 3x+2 + 3x+ 3 = 3159
|x + 4| + 45 = 245
|x + 4| = 200
x + 4 = 200 => x = 196
x + 4 = -200 => x = -204
b) 3x+1 + 3x+2 + 3x+3 = 3159
3x+1.(1 + 3 + 9) = 3159
3x+1 . 13 = 3159
3x+1 = 3159 : 13 = 243
3x+1 = 35
x + 1 = 5 => x= 4
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a,/x+4/=245-45=200
<=>x+4=200 hoặc x+4=-200
<=>x=196 hoặc x=-204
3^x+1+3^x+2+3^x+3=3159
=>3^x.(3+3^2+3^3)=3159
=>3^x.39=3159
=>3^x=3159:39=81=3^4
=>x=4
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a. |x+4|+45=245
|x+4|=245-45
|x+4|=200
Vì |200|=|-200|=200
=> x+4 thuộc {-200;200}
=> x thuộc {-204;204}
Vậy....
b. 3x+1+3x+2+3x+3=3159
3x(3+32+33)=3159
3x.39=3159
3x=3159:39
3x=81
3x=34
=> x=4
Vậy....
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3x+3 + 3x+2 + 3x = 3159
Ta có:
\(3^{x+3}+3^{x+2}+3^x=3159\)
\(3^x\left(3^3+3^2+3\right)=3159\)
\(3^x.39=3159\)
\(3^x=81\)
\(3^x=3^4\)
\(x=4\)
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tìm x biết; a,(3x-2)^2=(3x-5)^2 b,2x+2^x+1+2^x+3=480 c,3^x-1+3^x+3^x+1=3159
. Tìm x biết rằng:
a)(x + 1)3 – (x + 2)(x – 1)2 – 3(x – 3)(x + 3) = 5
b)(x + 1)3 + (x – 1)3 = (x + 2)3 + (x – 2)3
c) (x + 1)3 - (x - 1)3 - 6(x - 1)2 = -10
a: Ta có: \(\left(x+1\right)^3-\left(x+2\right)\left(x-1\right)^2-3\left(x-3\right)\left(x+3\right)=5\)
\(\Leftrightarrow x^3+3x^2+3x+1-\left(x+2\right)\left(x^2-2x+1\right)-3\left(x^2-9\right)=5\)
\(\Leftrightarrow x^3+3x^2+3x+1-\left(x^3-2x^2+x+2x^2-4x+2\right)-3\left(x^2-9\right)=5\)
\(\Leftrightarrow x^3+3x^2+3x+1-x^3+3x-2-3x^2+9=5\)
\(\Leftrightarrow6x=-3\)
hay \(x=-\dfrac{1}{2}\)
b: Ta có: \(\left(x+1\right)^3+\left(x-1\right)^3=\left(x+2\right)^3+\left(x-2\right)^3\)
\(\Leftrightarrow x^3+3x^2+3x+1+x^3-3x^2+3x-1=x^3+6x^2+12x+8+x^3-6x^2+12x-8\)
\(\Leftrightarrow2x^3+6x=2x^3+24x\)
\(\Leftrightarrow x=0\)
c: Ta có: \(\left(x+1\right)^3-\left(x-1\right)^3-6\left(x-1\right)^2=-10\)
\(\Leftrightarrow x^3+3x^2+3x+1-x^3+3x^2-3x+1-6x^2+12x-1=-10\)
\(\Leftrightarrow12x=-11\)
hay \(x=-\dfrac{11}{12}\)
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(X-1)^3 = (1-x)^2
1. (x-6)^2 = 2(x-6)
2. 2(x-3)^2 = (x-3)(x+5)
3. 4(x-3)=2x-5(2x+3)
4. x2 +4 -2 (x-1) = (x-2)^2
5. x-3/5 = 6 - 1-2x/3
6. x+2 = 6-5x/2
7. x+2/5 - x+3 = x-2/2
8. 2x-5/x-4 = 2x+1/x+2
9. X+3/x-3 - x-1/x+3 = x2 + 4x + 6/x2 -9
10. 3x-3/x2-9 -1/x-3 = x+1/x+3
11. X+1/x-1 - x-1/x+1 = 4/x2 -1
Bài dài quá, lần sau chia nhỏ câu hỏi nhé!!!!!
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a, (3x+2)2 - (3x-2)2 =5x+38 b, 3(x-2)2 +9(x-1) =3(x2+x-3)
c, (x+3)3 -(x-3)2 -(x-3)2 =6x+18 d, (x-1)3-x(x+1)2=5x(2-x)-11(x+2)
e, (x+1)(x2-x+1)-2x=x(x-1)(x+1) f, (x-2)3+(3x-1)(3x+1)=(x+1)3
a: =>9x^2+12x+4-9x^2+12x-4=5x+38
=>24x=5x+38
=>19x=38
=>x=2
e: =>x^3+1-2x=x^3-x
=>-2x+1=-x
=>-x=-1
=>x=1
f: =>x^3-6x^2+12x-8+9x^2-1=x^3+3x^2+3x+1
=>12x-9=3x+1
=>9x=10
=>x=10/9
b: \(\Leftrightarrow3x^2-12x+12+9x-9=3x^2+3x-9\)
=>-3x+3=3x-9
=>-6x=-12
=>x=2
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Tìm x biết : 6(x+2)(x-3)-3(x-2)^2-3(x-1)(x+1)=1
3(x+2)^2+(2x-1)^2-7(x+3)(x-3)=36
(x-1)(x^2+x+1)+x(x+2)(2-x)=5
(x-1)^3-(x+3)(x^2-3x+9)+3(x^2-4)=2
Tìm x biết : 6(x+2)(x-3)-3(x-2)^2-3(x-1)(x+1)=1
3(x+2)^2+(2x-1)^2-7(x+3)(x-3)=36
(x-1)(x^2+x+1)+x(x+2)(2-x)=5
(x-1)^3-(x+3)(x^2-3x+9)+3(x^2-4)=2