2.3 mũ x = 10.3 mũ 12 + 8.27 mũ 4
2.3 mũ x =10.3 mũ 12 + 8.27 mũ 4
2.3x = 10.312 + 8.274
=> 2.3x = 10.312 + 23 . (33)4
=> 2.3x = 10.312 + 8.312
=> 2.3x = (10 + 8).312
=> 2.3x = 18.312
=> 2.3x = 2.32 . 312
=> 2.3x = 2.314
=> x = 14
\(2.3^x=10.3^{12}+8.27^4\)
\(\Leftrightarrow2.3^x=2.5.3^{12}+2^3.\left(3^3\right)^4\)
\(\Leftrightarrow2.3^x=2.5.3^{12}+2^3.3^{12}\)
\(\Leftrightarrow2.3^x=2.3^{12}\left(5+2^2\right)\)
\(\Leftrightarrow2.3^x=2.3^{12}.9\)
\(\Leftrightarrow2.3^x=2.3^{12}.3^2\)
\(\Leftrightarrow2.3^x=2.3^{14}\)
\(\Leftrightarrow x=14\)
Vậy x=14
Hok Tốt !!!!!!!!!!!!!!!!!!!!!!!
\(2\cdot3^x=10\cdot3^{12}+8\cdot27^4\)
\(2\cdot3^x=2\cdot5\cdot3^{12}+2^3\cdot\left(3^3\right)^4\)
\(2\cdot3^x=2\cdot5\cdot3^{12}+2^3\cdot3^{12}\)
\(2\cdot3^x=2\cdot3^{12}\left(5+2^2\right)\)
\(3^x=3^{12}\left(5+4\right)\)
\(3^x=3^{12}\cdot9\)
\(3^x=3^{12}\cdot3^2\)
\(3^x=3^{14}\)
x = 14
Tìm x, biết
A) 4 mũ x. 4=64
B)3 mũ x. 3 mũ 21
C) 5 mũ : 25= 5 mũ 27
D) 2 mũ x :16 =128
E) 2.3 mũ x =10.3 mũ 12+8.12 mũ 4
F) 2 mũ 4.x-3 mũ 2.x=145-255:51
Bài 3 (2 điểm): Tìm x
a) 25 – 3.(6 – x) = 22
b) [(2x – 11):3 + 1].5 = 20
c) (25 - 2x) mũ 3 : 5 - 3 mũ 2 = 4 mũ 2
d) 2.3x = 10.3 mũ12 + 8.27 mũ4
a)
\(\text{( 25 – 2x )³ : 5 – 3^2 = 4^2}\)
\(\text{( 25 – 2x )³ : 5 – 9 = 16}\)
\(\text{( 25 – 2x )³ : 5 = 16 + 9}\)
\(\text{( 25 – 2x )³ : 5 = 25}\)
\(\text{( 25 – 2x )³ = 25 . 5}\)
\(\text{( 25 – 2x )³ = 125}\)
\(\text{( 25 – 2x )³ = 5³}\)
\(\text{25 – 2x = 5}\)
\(\text{2x = 25 – 5}\)
\(\text{2x = 20}\)
\(\text{x = 10}\)
\(\text{________________________________________}\)
b)
\(\text{2.3^x = 10.3^12 + 8.27^4}\)
\(\text{2.3^x = 10.3^12 + 8.(3^3)^4}\)
\(\text{2.3^x = 3^12 . (10+8)}\)
\(\text{2.3^x = 3^12 . 18}\)
\(\text{3^x = 3^12 . 18:2}\)
\(\text{3^x = 3^12 . 9}\)
\(\text{3^x = 3^12 . 3^2}\)
\(\text{3^x = 3^14}\)
\(\text{=> x=14}\)
2.3^x =10.3^12 +8.27^4
tìm x 2.3^x=10.3^12+8.27^4
\(2.3^x=10\cdot3^{12}+8.27^4\)
\(10.3^{12}+8.27^4=10.3^{12}+8.3^{12}\)
\(10.3^{12}+8.3^{12}=3^{12}\cdot\left(10+8\right)=3^{12}\cdot18=3^{12}\cdot2\cdot3^2=3^{14}\cdot2\)
=>x = 14
Tìn x :
2.3 mũ x = 10 . 3 mũ 12 + 8 . 27 mũ 4
\(2.3^x=10.3^{12}+8.27^4\\ \Rightarrow2.3^x=10.3^{12}+8.\left(3^3\right)^4\\ \Rightarrow2.3^x=10.3^{12}+8.3^{12}\\ \Rightarrow2.3^x=3^{12}\left(10+8\right)\\ \Rightarrow2.3^x=3^{12}.18\)
\(=>3^x=3^{12}.18:2\\ \Rightarrow3^x=3^{12}.3^2\\ \Rightarrow3^x=3^{10}\)
tìm x
2.3^x = 10.3^12+8.27^4
<=>2.3x=9565938 tính ra số hơi to ^^
=>3x2=2.4782696 ( 2 vế rút gọn 2 )
=>3x=4782969
=>x=14
Rút gọn:
2 mũ 10.3 mũ 10-2 mũ 10.3 mũ 9/2 mũ 9.3 mũ 10
\(\frac{2^{10}\cdot3^{10}-2^{10}\cdot3^9}{2^9\cdot3^{10}}\)\(=\frac{2^{10}\cdot3^9\left(3-1\right)}{2^9\cdot3^{10}}\)\(=\frac{2\cdot2}{3}=\frac{4}{3}\)
Vậy \(\frac{2^{10}\cdot3^{10}-2^{10}\cdot3^9}{2^9\cdot3^{10}}=\frac{3}{4}\)