1, a,81 mũ 2 :27 mũ 5 b, 6 mũ 4 . 32 mũ 3 c, 25 mũ 5 .125 mũ 3 2, 4 mũ n-1=64 5 mũ n+2=625 78<3 mũ n=1<813 16<2 mũ n-2<128 giúp với ạ còn tiếng nx làm nộp r
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Bài 6 :
a) \(\dfrac{625}{5^n}=5\Rightarrow\dfrac{5^4}{5^n}=5\Rightarrow5^{4-n}=5^1\Rightarrow4-n=1\Rightarrow n=3\)
b) \(\dfrac{\left(-3\right)^n}{27}=-9\Rightarrow\dfrac{\left(-3\right)^n}{\left(-3\right)^3}=\left(-3\right)^2\Rightarrow\left(-3\right)^{n-3}=\left(-3\right)^2\Rightarrow n-3=2\Rightarrow n=5\)
c) \(3^n.2^n=36\Rightarrow\left(2.3\right)^n=6^2\Rightarrow\left(6\right)^n=6^2\Rightarrow n=6\)
d) \(25^{2n}:5^n=125^2\Rightarrow\left(5^2\right)^{2n}:5^n=\left(5^3\right)^2\Rightarrow5^{4n}:5^n=5^6\Rightarrow\Rightarrow5^{3n}=5^6\Rightarrow3n=6\Rightarrow n=3\)
Bài 7 :
a) \(3^x+3^{x+2}=9^{17}+27^{12}\)
\(\Rightarrow3^x\left(1+3^2\right)=\left(3^2\right)^{17}+\left(3^3\right)^{12}\)
\(\Rightarrow10.3^x=3^{34}+3^{36}\)
\(\Rightarrow10.3^x=3^{34}\left(1+3^2\right)=10.3^{34}\)
\(\Rightarrow3^x=3^{34}\Rightarrow x=34\)
b) \(5^{x+1}-5^x=100.25^{29}\Rightarrow5^x\left(5-1\right)=4.5^2.\left(5^2\right)^{29}\)
\(\Rightarrow4.5^x=4.25^{2.29+2}=4.5^{60}\)
\(\Rightarrow5^x=5^{60}\Rightarrow x=60\)
c) Bài C bạn xem lại đề
d) \(\dfrac{3}{2.4^x}+\dfrac{5}{3.4^{x+2}}=\dfrac{3}{2.4^8}+\dfrac{5}{3.4^{10}}\)
\(\Rightarrow\dfrac{3}{2.4^x}-\dfrac{3}{2.4^8}+\dfrac{5}{3.4^{x+2}}-\dfrac{5}{3.4^{10}}=0\)
\(\Rightarrow\dfrac{3}{2}\left(\dfrac{1}{4^x}-\dfrac{1}{4^8}\right)+\dfrac{5}{3.4^2}\left(\dfrac{1}{4^x}-\dfrac{1}{4^8}\right)=0\)
\(\Rightarrow\left(\dfrac{1}{4^x}-\dfrac{1}{4^8}\right)\left(\dfrac{3}{2}+\dfrac{5}{3.4^2}\right)=0\)
\(\Rightarrow\dfrac{1}{4^x}-\dfrac{1}{4^8}=0\)
\(\Rightarrow\dfrac{4^8-4^x}{4^{x+8}}=0\Rightarrow4^8-4^x=0\left(4^{x+8}>0\right)\Rightarrow4^x=4^8\Rightarrow x=8\)
a) \(2^5:8^4=2^5:\left(2^3\right)^4=2^5:2^{12}=2^{-7}=\frac{1}{2^7}\)\(=\left(\frac{1}{2}\right)^7\)
b) \(25^6:125^3=\left(5^2\right)^6:\left(5^3\right)^3=5^{12}:5^9=5^3\)
c) \(625^2:25^7=\left(5^4\right)^2:\left(5^2\right)^7=5^8:5^{14}=5^{-6}=\frac{1}{5^6}=\left(\frac{1}{5}\right)^6\)
d) \(12^3.3^3=\left(12.3\right)^3=36^3\)
e) \(32^2:2^4=\left(2^5\right)^2:2^4=2^{10}:2^4=2^6\)
g) \(64.2:2^5=2^6.2:2^5=2^7:2^5=2^2\)
Mk làm hộ bn rùi đó nhớ ủng hộ mk nha ^_^
a) (1 phần 2 ) mũ 7
b) 5 mũ 3
c) (1 phần 5 ) mũ 6
d) 36 mũ 3
e) 2 mũ 6
g) 2 mũ 2
a) Ta có: \(3^{54}=\left(3^6\right)^9=729^9\)
Lại có: \(2^{81}=\left(2^9\right)^9=512^9\)
Ta có: \(729^9>512^9\Rightarrow3^{54}>2^{81}\)
b) Ta có: \(5\cdot125\cdot625=5^1\cdot5^3\cdot5^4=5^8\)
Lại có: \(625^3=\left(5^4\right)^3=5^{12}\)
Ta có: \(5^8< 5^{12}\Rightarrow5\cdot125\cdot625< 625^3\)
c) Xét: \(8^4\cdot16^3\cdot32\)
\(=\left(2^3\right)^4\cdot\left(2^4\right)^3\cdot2^5\)
\(=2^{12}\cdot2^{12}\cdot2^5\)
\(=2^{29}\)
Xét: \(64^4\cdot8^2\)
\(=\left(2^6\right)^4\cdot\left(2^3\right)^2\)
\(=2^{24}\cdot2^6\)
\(=2^{30}\)
Ta có: \(2^{29}< 2^{30}\Rightarrow8^4\cdot16^3\cdot32< 64^4\cdot8^2\)
3.
a) \(\left(x-1\right)^3=125\)
=> \(\left(x-1\right)^3=5^3\)
=> \(x-1=5\)
=> \(x=5+1\)
=> \(x=6\)
Vậy \(x=6.\)
b) \(2^{x+2}-2^x=96\)
=> \(2^x.\left(2^2-1\right)=96\)
=> \(2^x.3=96\)
=> \(2^x=96:3\)
=> \(2^x=32\)
=> \(2^x=2^5\)
=> \(x=5\)
Vậy \(x=5.\)
c) \(\left(2x+1\right)^3=343\)
=> \(\left(2x+1\right)^3=7^3\)
=> \(2x+1=7\)
=> \(2x=7-1\)
=> \(2x=6\)
=> \(x=6:2\)
=> \(x=3\)
Vậy \(x=3.\)
Chúc bạn học tốt!
\(4^8.2^{20}=2^{16}.2^{20}=2^{36}\)
\(9^{12}.27^5.81^4=3^{24}.3^{15}.3^{16}=3^{55}\)
mk chỉnh đề
\(64^3.4^5.16^2=4^9.4^5.4^4=4^{18}\)
\(25^{20}.125^4=5^{40}.5^{12}=5^{52}\)
\(x^7.x^4.x^3=x^{14}\)
a) 2x = 16 e) 12x = 144
2x = 24 12x = 122
=> x = 4 => x = 2
b) 2x+1 = 16 các câu còn lại tương tự nhé nhiều quá
2x+1 = 24
x + 1 = 4
=> x = 3
c) 5x+1 = 125
5x+1 = 53
x + 1 = 3
=> x = 2
d) 52x - 1 = 125
52x-1 = 53
2x - 1 = 3
2x = 4
=> x = 2
a)Ta có : 2x = 16
2x = 24
=> x = 4
b) Ta có: 2x+1 = 16
2x+1 = 24
=> x+1 = 4
=> x = 4-1
=> x = 3
Mấy câu sau tương tự vậy đó để hôm khác mình làm tiếp cho bây giờ mình đi ngủ đã buồn ngủ quá hihi ! ^-^
Học tốt nha bạn !
`#3107.101107`
a)
`64^150` và `4^450`
Ta có:
`64^150 = (4^3)^150 = 4^(3*150) = 4^450`
Vì `450 = 450 => 4^450 = 4^450 => 64^150 = 4^450`
Vậy, `64^150 = 4^450`
b)
`81^64` và `27^100`
Ta có:
`81^64 = (3^4)^64 = 3^(4*64) = 3^256`
`27^100 = (3^3)^100 = 3^(3*100) = 3^300`
Vì `256 < 300 => 3^256 < 3^300 => 81^64 < 27^100`
Vậy, `81^64 < 27^100`
c)
`125^1000` và `25^3000`
Ta có:
`125^1000 = (5^3)^1000 = 5^(3*1000) = 5^3000`
Vì `5 < 25 => 5^3000 < 25^3000 => 125^1000 < 25^3000`
Vậy, `125^1000 < 25^3000`
d)
`4^30` và `3^40`
Ta có:
`4^30 = 4^(3*10) = (4^3)^10 = 64^10`
`3^40 = 3^(4*10) = (3^4)^10 = 81^10`
Vì `64 < 81 => 64^10 < 81^10 => 4^30 < 3^40`
Vậy, `4^30 < 3^40`
m)
`2^5000` và `5^2000`
Ta có:
`2^5000 = 2^(5*1000) = (2^5)^1000 = 32^1000`
`5^2000 = 5^(2*1000) = (5^2)^1000 = 25^1000`
Vì `32 > 25 => 32^1000 > 25^1000 => 2^5000 > 5^2000`
Vậy, `2^5000 > 5^2000`
h)
`6^450` và `3^750`
Ta có:
`6^450 = 6^(150*3) = (6^3)^150 = 216^150`
`3^750 = 3^(150*5) = (3^5)^150 = 243^150`
Vì `216 < 243 => 216^150 < 243^150 => 6^450 < 3^750`
Vậy, `6^450 < 3^750`
0)
`333^444` và `444^333`
Ta có:
`333^444 = 333^(4*111) = (333^4)^111 = (3^4 *111^4)^111 = 81^111 * 111^444`
`444^333 = 444^(3*111) = (444^3)^111 = (4^3 * 111^3)^111 = 64^111 * 111^333`
Vì `81 > 64;` `111^444 > 111^333`
`=> 81^111 * 111^444 > 64^111 * 111^333`
Vậy, `333^444 > 444^333.`
a) Ta có:
\(64^{150}=\left(2^6\right)^{150}=2^{900}\)
\(4^{450}=\left(2^2\right)^{450}=2^{900}\)
Mà: \(2^{900}=2^{900}\Rightarrow64^{150}=4^{450}\)
b) Ta có:
\(81^{64}=\left(3^4\right)^{64}=3^{256}\)
\(27^{100}=\left(3^3\right)^{100}=3^{300}\)
Mà: \(3^{300}>3^{256}\Rightarrow27^{100}>81^{64}\)
c) Ta có:
\(125^{1000}=\left(5^3\right)^{1000}=5^{3000}\)
Mà: \(25^{3000}>5^{3000}\Rightarrow25^{3000}>125^{1000}\)
d) Ta có:
\(4^{30}=\left(4^3\right)^{10}=64^{10}\)
\(3^{40}=\left(3^4\right)^{10}=81^{10}\)
Mà: \(81^{10}>64^{10}\Rightarrow3^{40}>4^{30}\)
m) Ta có:
\(2^{5000}=\left(2^5\right)^{1000}=32^{1000}\)
\(5^{2000}=\left(5^2\right)^{1000}=25^{1000}\)
Mà: \(25^{1000}< 32^{1000}\Rightarrow2^{5000}>5^{2000}\)
h) Ta có:
\(6^{450}=\left(6^3\right)^{150}=216^{150}\)
\(3^{750}=\left(3^5\right)^{150}=243^{150}\)
Mà: \(243^{150}>216^{150}\Rightarrow3^{750}>6^{450}\)
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