Tim x biet
a 2.3^x=162
b 2^x-15=17
c (7.x-11)=2^5.5^2+200
tìm số tự nhiên x biết
a)2^x-15=17
b)(7^x-11)^3=2^5.5^2+200
c)2.3^x=10.3^12+8.27^4
d)(2x-150^5=(2x-15)^3
2\(^x\)- 15 = 17
\(\Rightarrow\)2\(^x\) = 32
\(\Rightarrow\)x = 5
2^x-15=17
=>2^x=17+15
=2^x=32
=>2^x=2^5
=>x=5
Tìm x thuộc số tự nhiên biết
a 2.3^x=162
b 5^x=125
c 2^x-15=17
d (7^x-11)^3=2^5.5^2+200
e 3^2^x=81
f 5^2^x-^3-2.5^2=5^2.3
Tìm x biet x thuộc so tự nhien :
a) 2x-15=17
b) (7.x-11)=2^5.5^2+200
c) (2x-15)5=(2x-15)3
tim \(x\in\)N biet
a . \(x^{10}=x\)
b . \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
c . \(\left(7\times n-11\right)=2^5.5^2+200\)
a) \(x^{10}=x\)
\(\Rightarrow x^{10}-x=0\)
\(\Rightarrow x\left(x^9-1\right)=0\)
=> x=0 HOẶC \(x^9-1=0\)
=>x=0 HOẶC x=1
22) tim x thuoc n biết
a)2^x=16
b)4^x=64
c)15^x=225
d)2^x-15=17
e)2^x-64=2^6
f)(7x-11)^3=2^5.5^2+200
a) \(2^x=16\)
\(2^x=2^4\)
\(\Rightarrow x=4\)
vay \(x=4\)
b) \(4^x=64\)
\(4^x=4^3\)
\(\Rightarrow x=3\)
vay \(x=3\)
c) \(15^x=225\)
\(15^x=15^2\)
\(\Rightarrow x=2\)
vay \(x=2\)
d) \(2^x-15=17\)
\(2^x=32\)
\(2^x=2^5\)
\(\Rightarrow x=5\)
vay \(x=5\)
e) \(2^x-64=2^6\)
\(2^x=2^6+64\)
\(2^x=128\)
\(2^x=2^7\)
\(\Rightarrow x=7\)
vay \(x=7\)
f) \(\left(7x-11\right)^3=2^5.5^2+200\)
\(\left(7x-11\right)^3=800+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
\(\Rightarrow7x-11=10\)
\(\Rightarrow7x=21\)
\(\Rightarrow x=3\)
vay \(x=3\)
a) (7x-11)^3=2^5.5^2+200
b) 3^x+25=26.2^2+2.3^0
1. Tìm x:
a) \(2^x-15=17\)
b) \(\left(7x-11\right)^3=2^5.5^2+200\)
c) \(x^{10}=1^x\)
d) \(x^{10}=x\)
e)\(\left(2x-15\right)^5=\left(2x-15\right)^3\)
2. Tính:
\(A=\dfrac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right)^2}\)
a) 2x - 15 = 17
2x = 25
b) ( 7x - 11 )3 = 25. 52 + 200
(7x - 11)3 = 32 . 25 + 200
(7x -11)3 = 1000
(7x-11)3 = 103
7x - 11 = 10
7x = 10+11
7x = 21
x = 21 : 7
x = 3
like nha
tim x biet
\(\left(7x-11\right)^3=2^5.5^2+200\)
minh can cach lam gappppppp ai nhanh minh tk luon
\(\left(7x-11\right)^3=2^5.5^2+200\)
=> \(\left(7x-11\right)^3=32.25+200\)
=>\(\left(7x-11\right)^3=800+200\)
=>\(\left(7x-11\right)^3=1000\)
=>\(\left(7x-11\right)^3=10^3\)
=> \(7x-11=10\)
=>\(7x=21\)
=>\(x=3\)
Vậy x = 3
\(\left(7x-11\right)^3=2^5\cdot5^2+200\)
\(\left(7x-11\right)^3=800+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
\(\Rightarrow7x-11=10\)
\(7x=10+11\)
\(7x=21\)
\(x=21\div7\)
\(x=3\)
\(\left(7x-11\right)^3=2^5\cdot5^2+200\)
\(\left(7x-11\right)^3=32\cdot25+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
\(7x-11=10\)
\(7x=21\)
\(x=3\)
Tim x thuoc N biet
(7x-11)3=25.52 +200. ;b)3x+25=26.22+2.30.
2x+3.2=64 ;5x+1+5x=750
x15=x ;(x-5)4=(x-5)6
\(a,\left(7x-11\right)^3=2^5.5^2+200.\)
\(\left(7x+11\right)^3=32.25+200.\)
\(\left(7x+11\right)^3=800+200.\)
\(\left(7x-11\right)^3=1000.\)
\(\left(7x-11\right)^3=10^3.\)
\(\Rightarrow7x-11=10.\)
\(\Rightarrow x=\left(10+11\right):3=7\in Z.\)
Vậy.....
\(b,3^x+25=26.2^2+2.3^0.\)
\(3^x+25=26.4+2.\)
\(3^x+25=104+2.\)
\(3^x+25=106.\)
\(3^x=106-25.\)
\(3^x=81.\)
\(3^x=3^4\Rightarrow x=4\in Z.\)
Vậy.....
\(c,2^x+3.2=64.\)(có vấn đề).
\(d,5^{x+1}+5^x=750.\)
\(5^x.5^1+5^x+1=750.\)
\(5^x\left(5^1+1\right)=750.\)
\(5^x\left(5+1\right)=750.\)
\(5^x.6=750.\)
\(5^x=750:6.\)
\(5^x=125.\)
\(5^x=5^3\Rightarrow x=3\in Z.\)
Vậy.....
\(e,x^{15}=x.\)
\(\Rightarrow x\left(x^{14}-1\right)=0\Rightarrow\left\{{}\begin{matrix}x=0\\x=1\end{matrix}\right..\)
\(f,\left(x-5\right)^4=\left(x-5\right)^6.\)
\(\Leftrightarrow\left(x-5\right)^4-\left(x-5^6\right)=0.\)
\(\Leftrightarrow\left(x-5\right)^4\left[1-\left(x-5\right)^2\right]=0.\)
\(\Leftrightarrow\left(x-5\right)^4\left(1-x+5\right)\left(1+x-5\right)=0.\)
\(\Leftrightarrow\left(x-5\right)^4\left(6-x\right)\left(x-4\right)=0.\)
\(\Leftrightarrow\left(x-5\right)^4=0\Rightarrow x-5=0\Rightarrow x=5\in Z.\)
\(6-x=0\Rightarrow x=6\in Z.\)
\(x-4=0\Rightarrow x=4\in Z.\)
Vậy.....