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\(3^{x-1}+5.3^{x-1}=486\)
\(\Rightarrow3^{x-1}.\left(5+1\right)=486\)
\(3^{x-1}.6=486\)
\(3^{x-1}=81\)
\(3^{x-1}=3^4\)
\(\Rightarrow x-1=4\)
\(\Rightarrow x=5\)
<=> 3x-1 +5.3x-1 =486
<=> 3x-1 . (1+5) = 486
<=> 3x-1 . 6 =486
<=> 3x-1 = 486 :6
<=> 3x-1 = 81
<=> 3x-1 = 34
<=> X-1=4
<=> X = 4+1
<=> X=5
\(=>2\cdot4^x+64\cdot4^x=1056\)
\(=>4^x\cdot\left(2+64\right)=1056\)
\(=>4^x=1056:66=16\)
\(=>4^x=4^2\)
\(=>x=2\)
ti ck nha
2.22x + 43.4x = 1056
=> 2.4x + 43.4x = 1056
=> (2 + 64).4x = 1056
=> 66.4x = 1056
=> 4x = 1056 : 66
=> 4x = 16
=> 4x = 42
=> x = 2
7.4x - 1 + 4x + 1 = 23
=> 7.4x.1/4 + 4x.4 = 23
=> (7/4 + 4).4x = 23
=> 23/4.4x = 23
=> 4x = 23 : 23/4
=> 4x = 4
=> x = 1
3x + 2 - 5.3x = 36
=> 3x.9 - 5.3x = 36
=> 3x.(9 - 5) = 36
=> 3x.4 = 36
=> 3x = 36 : 4
=> 3x = 9 = 32
=> 3x = 2
Bài làm:
Ta có: \(\left(593x+2^6\right).5^4=2.5^8\)
\(\Leftrightarrow593x+64=2.5^4=1250\)
\(\Leftrightarrow593x=1186\)
\(\Rightarrow x=2\)
a) 0 : x = 0
=> x \(\in\)N ( x \(\ne\)0 )
b) 3x = 9
=> x = 2
c) 4x = 64
=> x = 3
d) 2x = 16
=> x = 4
e) 9x-1 = 9
9 = 91
=> x = 1 + 1 = 2
x4 = 16
=> x = 2
g) 2x : 25 = 1
Quy ước a0 = 1 , ta suy ra : x = 5
Giải ko giải thích , bỏ qua nhá :))
a.
(-2)4.17.(-3)0.(-5)6.(-12n)
=16.17.1.15625.-1
=(16.15625).[1.(-1)].17
=250000.(-1).17
=4250000
b.3(2x2-7)=33
2x2-7 =33:3
2x2-7 =11
2x2 =11+7
2x2 =18
x2 =18:2
x2 =9
x2 =\(\left(\pm3^2\right)\)
\(\Rightarrow\) TH1: x2 =32 TH2: x2 =(-3)2
\(\Rightarrow\) x =3 \(\Rightarrow\)x =-3
Vậy x\(\in\left\{3;-3\right\}\)
\(A=3+3^2+3^3+3^4+...+3^{100}\)
\(3A=3^2+3^3+...+3^{101}\)
\(3A-A=\left[3^2+3^3+...+3^{101}\right]-\left[3+3^2+3^3+...+3^{100}\right]\)
\(2A=3^{101}-3\)
\(A=\frac{3^{101}-3}{2}\)
Ta lại có : \(2A+3=3^x\)
=> \(2\cdot\frac{3^{101}-3}{2}+3=3^x\)
=> \(3^{101}-3+3=3^x\)
=> 3101 = 3x
=> x = 101
Vậy x = 101
\(3A=3^2+3^3+...+3^{101}\)
\(\Rightarrow2A=3^{101}-3\)
\(\Rightarrow2A+3=3^{101}=3^x\)
\(\Rightarrow x=101\)
A, (2x+1)3=343
=> (2x+1)3=73
=> 2x + 1 = 7
=> 2x = 6
=> x = 3
B, 2x+2x+3=144
=> 2x+2x . 23 =144
=> 2x ( 1 + 23 ) =144
=> 2x ( 1 + 8 ) =144
=> 2x . 9 =144
=> 2 x = 16
=> 2 x = 2 4
=> x = 4
C, 3x+3x+2=2430
=> 3x+3x . 32 =2430
=> 3x . ( 1 + 32 ) =2430
=> 3x . ( 1 + 9 ) =2430
=> 3x . 10 =2430
=> 3x = 243
=> 3x = 3 5
=> x = 5
x + 4131 : 35 = 5.32
x+17=45
x=45-17
x=28
x+4131:35=5 x 32
x+17=45
x=45+17
x=62
HOK TỐT