a, x^10=x
b, x^10=1^x
c, (2x-15)^5=(2x-15)^3
Tìm x
a,x^10=10^x
b, x^10=x
c, (2x-15)^5=(2x-15)^3
tìm x, biết x là số tự nhiên
b)2.3^x=162
c)(2x-15)^5=(2x-15)^3
d)3^(x+2) -5.3^x
e)7.4^(x-1)+4(x+1)=23
f)2.2^(2x)+4^3.4^x=1056
10 -{[(x:3+17):10+3.2^4]:10}=5
gấp, mọi ng giúp mình với
`#3107`
b)
`2.3^x = 162`
`\Rightarrow 3^x = 162 \div 2`
`\Rightarrow 3^x = 81`
`\Rightarrow 3^x = 3^4`
`\Rightarrow x = 4`
Vậy, `x = 4`
c)
`(2x - 15)^5 = (2 - 15)^3`
\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`
\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`
\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)
Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)
`d)`
\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!
`e)`
\(7\cdot4^{x-1}+4^{x-1}=23?\)
\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)
Bạn xem lại đề!
`f)`
\(2\cdot2^{2x}+4^3\cdot4^x=1056\)
\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)
Vậy, `x = 2`
_____
\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)
\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)
\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)
\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)
\(\Rightarrow\left(x\div3+17\right)\div10=2\)
\(\Rightarrow x\div3+17=20\)
\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)
Vậy, `x = 9.`
Tìm x
a) x10 = 1x
b) x10 = x
c) ( 2x - 15 )5 = ( 2x - 15 )3
x10 = x
x 10- x = 0
x9. x - x. x1 = 0
x.(x9-x1) = 0
=>x=0
x9-1=0=> x9 = 1=> x=1
vậy x=1;0
x^10=1^x
x^10=x
(2x-15)^5=(2x-15)^3
a: \(\Leftrightarrow x^{10}=1\)
=>x=1 hoặc x=-1
b: \(\Leftrightarrow x^{10}-x=0\)
\(\Leftrightarrow x\left(x^9-1\right)=0\)
=>x=0 hoặc x=1
c: \(\Leftrightarrow\left(2x-15\right)^3\cdot\left(2x-14\right)\left(2x-16\right)=0\)
hay \(x\in\left\{\dfrac{15}{2};7;8\right\}\)
Tìm x
a) x10 = 1x
b) x10 = x
c) ( 2x - 15 )5 = ( 2x - 15 )3
a) 2x + 5 = 3
b) x phần 30 = 3 phần 10 + -1 phần 15
c) ( x - 1/4 ) : 4/5 = 15/16
d) | 2x - 1/3 | = 2/9
a)x =-1
b)x = 7 phần 30
c)x = 1
d)x = 5/18
nếu đúng thì hãy cho mình nha
Tìm x
x^10=1^x
x^10= x
(2x - 15)^5 = (2x-15)^3
1. chứng tỏ rằng tổng mỗi tổng của hiệu sau là 1 số chính phương:
a) 3^2 +4^2 b)13^ - 5^2 c)1^5 +2^3 + 3^3 +4^3
2. tìm x biết:
a) x^10 = 1^x b)( 2x - 15)^5 = (2x - 15)^3 c) x^10 = x
Câu 2:
a: \(x^{10}=1^x\)
\(\Leftrightarrow x^{10}=1\)
=>x=1 hoặc x=-1
b: \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
\(\Leftrightarrow\left(2x-15\right)^3\left[\left(2x-15\right)^2-1\right]=0\)
\(\Leftrightarrow\left(2x-15\right)^3\cdot\left(2x-16\right)\left(2x-14\right)=0\)
hay \(x\in\left\{\dfrac{15}{2};8;7\right\}\)
c: \(x^{10}=x\)
\(\Leftrightarrow x\left(x^9-1\right)=0\)
=>x=0 hoặc x=1
Tìm x biết
a) x/2008- 1/10-1/15 -....-1/120=5/8
b) 1/3*5+1/5*7 +.....+1/(2x+1)*(2x+3)= 15/93