\(5^{3x}-2.5^5=5^5.3\)
5.3^x+6=2.5^5+3
Mũ cụ thể như thế nào vậy bạn?
5.3^x+6 là $5.3^{x+6}$ hay $5.3^x+6$?
2.5^5+3 là $2.5^{5+3}$ hay $2.5^5+3$??
Tìm số nguyên x , nếu biết
1. 7.4^x=7.4^3
2.3/2.5^x =3/2.5^12
3 . 2^x=2.2^8
4. 5.3^x=7.3^5-2.3^5
1) \(7.4^x=7.4^3\Leftrightarrow4^x=4^3;x=3\)
2) \(\frac{3}{2.5^x}=\frac{3}{2.5^{12}}\Leftrightarrow5^x=5^{12};x=12\)
\(2^x=2.2^8=2^9;x=9\)
4) \(5.3^x=7.3^5-2.3^5\Leftrightarrow5.3^x=3^5.\left(7-2\right)\)
\(\Leftrightarrow3^5.x=3^5.5;x=5\)
Tìm x biết:
a) 5^x+1 - 2.5^x = 75.
b)9^x+1 - 5.3^2x = 324.
a) 5x + 1 - 2.5x = 75
<=> 5x.5 - 2.5x = 75
<=> 5x.3 = 75
<=> 5x = 25
<=> 5x = 52
<=> x = 2
Vậy x = 2
b) 9x + 1 - 5.32x = 324
<=> (32)x + 1 - 5.32x = 324
<=> 32x + 2 - 5.32x = 324
<=> 32x.32 - 5.32x = 324
<=> 32x . 4 = 324
<=> 32x = 81
<=> 32x = 34
<=> 2x = 4
<=> x = 2
Vậy x = 2
a, \(5.3^x=5.3^4\)
b, \(5.3^x=7.3^5-2:3^5\)
c, \(5^{x+4}-3.5^{x+3}=2.5^{11}\)
d, \(2^x+2^{x+1}+2^{x+2}+2^{x+3}+2^{x+4}+2^{x+5}=480\)
Làm đầy theo tính ra kết quả thì mk với tik
c, \(5^{x+4}-3\cdot5^{x+3}=2\cdot5^{11}\)
\(\Leftrightarrow5^{x+3}\cdot5-3\cdot5^{x+3}=2\cdot5^{11}\)
\(\Leftrightarrow5^{x+3}\left(5-3\right)=2\cdot5^{11}\)
\(\Leftrightarrow5^{x+3}\cdot2=2\cdot5^{11}\)
\(\Leftrightarrow5^{x+3}=5^{11}\)
\(\Leftrightarrow x+3=11\)
\(\Leftrightarrow x=8\)
Vậy x = 8
d, \(2^x+2^{x+1}+2^{x+2}+2^{x+3}+2^{x+4}+2^{x+5}=480\)
\(\Leftrightarrow2^x\left(1+2+2^2+2^3+2^4+2^5\right)=480\)
\(\Leftrightarrow2^x\cdot63=480\)
\(\Leftrightarrow2^x=\frac{160}{21}\)
\(\Leftrightarrow x\approx2,93\)
bn nào trả lời hộ mk ik
đang gấp !!!
Tìm x biết:
5^x+1 5^2x + 2.5^3x = 875
Tìm x biết:
5^x+1 5^2x + 2.5^3x = 875
tính bằng cách thuận tiện nhất
a/2.5*9.3*4 b/ 0.5*3.8*2
c/7.61*5*0.2 c/5.3*6.7+6.7*4.7
a) 2,5x9,3x4=(2,5x4)x9,3=10x9,3=93
b) 0,5x3,8x2=(0,5x2)x3,8=1x3,8=3,8
c)7,61x5x0,2=7,61x(5x0,2)=7,61x1=7,61
d) 5,3x6,7+6,7x4,7=6,7x(5,3+4,7)=6,7x10=67
\(5.3^x=5.3^4\)
\(5.3^x=7.3^5-2:3^5\)
5.3x = 5.34
=> x = 4
5.34 = 7.35 - 2.35
= 35 . (7 - 2)
= 5. 35
=> 3x = 35
=> x = 5
a) Ta có: \(5\cdot3^x=5\cdot3^4\)
\(\Leftrightarrow3^x=3^4\)
hay x=4
Tim x: 6^2-(x+3)=45
125-5.(3x-1)=5^5.5^3
4^x+1+4^0=65
70-5.(x-3)=5.3^2
\(6^2-\left(x+3\right)=45\)
\(36-\left(x+3\right)=45\)
\(x+3=35-45\)
\(x+3=-10\)
\(x=-13\)
\(6^2-\left(x+3\right)=45\)
\(\Rightarrow36-\left(x+3\right)=45\)
\(\Rightarrow x+3=36-45\)
\(\Rightarrow x+3=-9\)
\(\Rightarrow x=-9-3=-12\)
\(125-5\left(3x-1\right)=5^5.5^3\)
\(\Rightarrow5^3-5\left(3x-1\right)=5^5.5^3\)
\(\Rightarrow5^3-15x+5=5^5.5^3\)
\(\Rightarrow5\left(5^2-3x+1\right)=5^5.5^3\)
\(\Rightarrow5^2-3x+1=5^5.5^3:5\)
\(\Rightarrow25-3x+1=5^7\)
Từ đây làm nốt nhé
\(4^x+1+4^0=65\)
\(\Rightarrow4^{x+1}+1=65\)
\(\Rightarrow4^{x+1}=64\)
\(\Rightarrow4^{x+1}=4^3\)
\(\Rightarrow x+1=3\)
\(\Rightarrow x=2\)
\(70-5\left(x-3\right)=5.3^2\)
\(\Rightarrow70-5\left(x-3\right)=5.9=45\)
\(\Rightarrow5\left(x-3\right)=70-45=25\)
\(\Rightarrow x-3=25:5=5\)
\(\Rightarrow x=8\)
Chúc em học tốt hơn nhé!!