2 mũ x + 5.2 mũ x+2=168
2 mũ x + 5.2 mũ x+2 = 168
\(2^x+5\cdot2^{x+2}=168\)
=>\(2^x+20\cdot2^x=168\)
=>\(21\cdot2^x=168\)
=>\(2^x=8=2^3\)
=>x=3
\(2^x+5.2^{x+2}=168\\ \Leftrightarrow2^x.\left(1+5.2^2\right)=168\\ \Leftrightarrow2^x.21=168\\ \Leftrightarrow2^x=\dfrac{168}{21}=8=2^3\\ Vây:x=3\)
2 mũ x + 2 mũ x+3= 144
2 mũ x-1 + 5.2 mũ x-2= 224
a) \(2^x+2^{x+3}=144\)
\(2^x\left(1+2^3\right)=144\)
\(2^x.9=144\)
\(2^x=144:9=16\)
=> \(2^x=2^4\Rightarrow x=4\)
b) \(2^{x-1}+5.2^{x-2}=224\)
\(2^{x-2}\left(2+5\right)=224\)
\(2^{x-2}.7=224\Rightarrow2^{x-2}=32\Rightarrow2^{x-2}=2^5\)
=> x - 2 = 5 => x = 7
a ) 2x + 2x + 3 = 144
=> 2x . ( 1 + 23 ) = 144
=> 2x . 9 = 144
=> 2x = 16
=> 2x = 24
=> x = 4
Vậy x = 4
b ) 2x - 1 + 5. 2x - 2 = 224
=> 2x - 2 . ( 2 + 5 ) = 224
=> 2x - 2 . 7 = 224
=> 2x - 2 = 32
=> 2x - 2 = 25
=> x - 2 = 5
=> x = 7
Vậy x = 7
5.2 mũ x+1.2 mũ -2-2 mũ x=384
\(5\cdot2^x+1\cdot2^{x-2}-2^x=384\)
=>\(4\cdot2^x+2^x\cdot\dfrac{1}{4}=384\)
=>2^x=1536/17
hay \(x\in\varnothing\)
3 mũ 2 .(x+14)- 5 mũ 2 =5.2 mũ 2
Tìm x
8 mũ x = 2 mũ 111
2 mũ x + 5.2 mũ x = 48
2 mũ x + 3.2 mũ x-1 = 40
8x=2111
=>(23)x=2111
=>23x=2111
=>3x=111
=>x=37
2x+5.2x=48
=>2x.6=48
=>2x=8=23
=>x=3
Câu cuối ko làm đc nha
a. 8x = 2111
23x = 2111
3x = 111
x = 111:3
x = 37
b. 2x + 5.2x = 48
2x(5 + 1 )= 48
2x.6 = 48
2x = 48 : 6
2x = 8
2x = 23
x = 3
c. 2x + 3.2x-1 = 40
2x(3:2 +1 ) = 40
2x . \(\frac{5}{2}\) = 40
2x = 40 : \(\frac{5}{2}\)
2x = 16
2x = 24
x = 4
+) \(8^x=2^{111}\)
\(\Rightarrow\left(2^3\right)^x=2^{111}\)
\(\Rightarrow2^{3x}=2^{111}\)
\(\Rightarrow3x=111\)
\(\Rightarrow x=111:3\)
\(\Rightarrow x=37\)
Vậy x = 37
+) \(2^x+5\times2^x=48\)
\(\Rightarrow2^x\times\left(1+5\right)=48\)
\(\Rightarrow2^x\times6=48\)
\(\Rightarrow2^x=48:6\)
\(\Rightarrow2^x=8\)
\(\Rightarrow2^x=2^3\)
\(\Rightarrow x=3\)
Vậy x = 3
+) \(2^x+3\times2^{x-1}=40\)
\(\Rightarrow2^x+3\times2^x:2=40\)
\(\Rightarrow2^x+3\times2^x\times\frac{1}{2}=40\)
\(\Rightarrow2^x+2^x\times\left(3\times\frac{1}{2}\right)=40\)
\(\Rightarrow2^x+2^x\times\frac{3}{2}=40\)
\(\Rightarrow2^x\times\left(1+\frac{3}{2}\right)=40\)
\(\Rightarrow2^x\times\frac{5}{2}=40\)
\(\Rightarrow2^x=40:\frac{5}{2}\)
\(\Rightarrow2^x=16\)
\(\Rightarrow2^x=2^4\)
\(\Rightarrow x=4\)
Vậy x = 4
_Chúc bạn học tốt_
Tìm X:
a, 25 + 3 ( x-8 ) = 106
b, 3 mũ 2 ( x+4 ) - 5 mũ 2 = 5.2 mũ 2
Tìm X:
a, 25 + 3 ( x-8 ) = 106
b, 3 mũ 2 ( x+4 ) - 5 mũ 2 = 5.2 mũ 2
3.(x-8) = 106-25
3.(x-8) = 81
x-8 = 81:3
x-8 = 27
x=35
\(a,25+3\left(x-8\right)=106\\ 3\left(x-8\right)=81\\ x-8=27\\ x=35\)
32 . (x + 4 ) - 52 = 5 . 22
9 . ( x + 4 ) - 25 = 20
9 . ( x + 4 ) = 20 + 25
9 . ( x + 4 ) = 45
( x + 4 ) = 45 : 9
x + 4 = 5
x = 5 - 4
x = 1
3 mũ 2 [x+4]-5 mũ 2 bằng 5.2 mũ 2
32 ((x + 4)-5)2 = 5x22
9 (( x + 4 ) - 5)2 = 20
????
Không cho điều kiện của x sao làm đc bạn
\(3^{2\left(x+4\right)}-5^2=5.2^2\)
\(3^{2\left(x+4\right)}-25=5.4\)
\(3^2.3^{x+4}=45\)
\(3^{x+4}=9\)
\(3^{x+4}=3^2\)
\(\Rightarrow x+4=2\)
\(x=-2\)
Vay ....
2 mũ x + 4. 2 mũ 11=5.2 mũ 5
Đề như này có vẻ hợp lí hơn:
\(2^x+4.2^x=5.2^5\)
\(\Leftrightarrow2^x\left(1+4\right)=5.2^5\)
\(\Leftrightarrow5.2^x=5.2^5\)
\(\Leftrightarrow x=5\)