Tìm x
\(3-5^{2x+1}-3.25^x=300\)
tìm x biết 3.52x+1-3.25x=300
a) Tìm \(n\in N\), biết:
\(3.5^{2n+1}-3.25^n=300\)
b) Tìm x để:
\(f\left(x\right)=6x^{^{ }4}-2x^3+5=5\)
a)\(3\cdot5^{2n+1}-3\cdot25^n=300\)
\(3\cdot5^{2n}\cdot5-3\cdot25^n=300\)
\(15\cdot25^n-3\cdot25^n=300\)
\(25^n\cdot12=300\)
\(25^n=25\)
\(\Rightarrow n=1\)
b)\(f\left(x\right)=6x^4-2x^3+5=5\)
\(6x^4-2x^3=0\)
\(6x^4=2x^3\)
\(3x^4=x^3\)
\(3x^4-x^3=0\)
\(x^3\left(3x-1\right)=0\)
\(\Rightarrow x^3=0\) hoặc 3x-1=0
\(\Rightarrow x=0,3x=1\)
\(\Rightarrow x=0,x=\frac{1}{3}\)(loại vì \(x\in N\))
Vậy x=0
\(3.5^{2x+1}-3.25^x=300\)
tìm x
\(3.5^{2x+1}\)- \(3.25^x\)=300
mong các bn giúp mik ^-^
Tìm x
a) \(9^{x+1}-5.3^{2x}=324\)
b) \(3.5^{2x+1}-3.25^x=300\)
c) \(16^x:4^x=16\)
d) \(2^{-1}.2^x+4.2^x=72\)
Tìm x :
3.5 2x+1 -3.25x = 300
8 x+3+ 8x - 3.4x+1 . 2x+4 = 2568
Tìm x biết : a) \(\left(x-5\right)^2=25\)
b) \(9^{x+1}-5.3^{2x}=324\)
c) \(3.5^{2x+1}-3.25^x=300\)
Tìm x trong đẳng thức
a, 5^-3.25^x - 5^3x
b, 3^(2x+6).(3x+9) = 1
c, 1/3.3^x = 73^2.9^2-2.3x
d, 9^x+1-5=3^2=324
Gíup mk vs mn ơi.. ❤❤
Tìm x
a) \(9^{x+1}-5.3^{2x}=324\)
b) \(3.5^{2x+1}-3.25^x=300\)
c) \(16^x:4^x=16\)
d) \(2^{-1}.2^x+4.2^x=72\)
b) 3.[52x+1 - (52)x] = 3.100
3( 52x+1-52x) = 3.100
-> 52x+1-52x = 100
mà 53-52= 100
-> 52x+1-52x = 53-52
Vậy x = 1
c) (42)x : 4x = 42
<=>42x-x =42
<=> 4x = 42
-> x=2
d) 2x( 0,5 +4) = 72
2x. 4,5 = 72
2x = 72:4,5 = 16
2x = 24 = 16
-> x= 4