\(2.2^2.2^3..........2^x=1024\)
Tìm số nguyên dương x biết
\(2.2^2.2^3.....2^x=1024\)
Có: 1024=2^10
=> 2.2^2.2^3......2^x=2^10
=> 1+2+3+...+x=10
1+2+3+...+x=1+2+3+4
=>x=4
Vậy x=4
Tìm x biết
2.2^2.2^3.2^4...2^x=1024
Mình giải không ra mong mọi người giúp đỡ
2.2^2.2^3.2^4......2^x = 1024
2^(1+2+...+x) = 2^10
=> 1+2 + 3+...+ x = 10
=>x.(1+x):2 = 10
=>x.(1+x) = 20
=> x = 4 (vì 4.5 =20)
Đúng cái gì cơ
1 Tìm x:
a) \(2.2^2.2^3...2^x=1024\) b) \(\frac{37-x}{x+13}=\frac{3}{7}\)
2. Tính :
\(\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}}+\left(\frac{50^2-15.125}{5^4}\right)^{2014}\)
Bài 1 )
a ) \(2.2^2.2^3.....2^x=1024\Leftrightarrow2^{1+2+....+x}=2^{10}\Leftrightarrow1+2+....+x=10\)
\(\Leftrightarrow\frac{x\left(x+1\right)}{2}=10\Leftrightarrow\left(x+1\right)x=20=4.5\Rightarrow x=4\)
b ) \(\frac{37-x}{x+13}=\frac{3}{7}\Leftrightarrow3x+39=259-7x\Leftrightarrow3x+7x=259-39\Leftrightarrow10x=220\Rightarrow x=22\)
Bài 2 ) \(\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}}+\left(\frac{50^2-15.125}{5^4}\right)^{2014}=\frac{1}{2}.8-\frac{2}{5}+\left(\frac{5^4.2^2-3.5^4}{5^4}\right)^{2014}\)
\(=4-\frac{2}{5}+\left[\frac{5^4\left(4-3\right)}{5^4}\right]^{2014}=\frac{18}{5}+1=\frac{23}{5}\)
Mình làm bài 1 thui nha, còn bài 2 thì còn tự tính là được thôi mừ !!!
Bài 1:
a) \(2.2^2.2^3...2^x=1024\)
\(=>2^{1+2+3+...+x}=2^{10}\)
\(< =>1+2+3+...+x=10\)
\(=>6+x=10\)
\(=>x=10-6\)
\(=>x=4.\)
Nếu đúng thì k cho mình nhá
Tìm số nguyên x, biết:
2.22.23.24 ... .2x = 1024
* Trả lời:
Ta có: \(1024=2^{10}\)
Lại có: \(2.2^2.2^3.2^4=2^{10}\)
\(\Rightarrow2^x=1\)
\(\Leftrightarrow x=0\) ( vì số nào mũ 0 cũng bằng 1)
a)\(\frac{x+1}{2}+\frac{x+1}{3}+\frac{x+1}{4}=\frac{x+1}{5}+\)\(\frac{x+1}{6}\)
b)\(\frac{x+1}{2009}+\frac{x+2}{2008}+\frac{x+3}{2007}=\)\(\frac{x+10}{2000}+\frac{x+11}{1999}+\frac{x+12}{1998}\)
c)\(2.2^2.2^3.2^4.........2^x=1024\)\(\left(x\in z\right)\)
Tìm x
b./ \(\Leftrightarrow\frac{x+1}{2009}+1+\frac{x+2}{2008}+1+\frac{x+3}{2007}+1=\frac{x+10}{2000}+1+\frac{x+11}{1999}+1+\frac{x+12}{1998}+1.\)
\(\Leftrightarrow\frac{x+2010}{2009}+\frac{x+2010}{2008}+\frac{x+2010}{2007}-\frac{x+2010}{2000}-\frac{x+2010}{1999}-\frac{x+2010}{1998}=0\)
\(\Leftrightarrow\left(x+2010\right)\left(\frac{1}{2009}+\frac{1}{2008}+\frac{1}{2007}-\frac{1}{2000}-\frac{1}{1999}-\frac{1}{1998}\right)=0\)(b)
Mà \(\frac{1}{2009}+\frac{1}{2008}+\frac{1}{2007}-\frac{1}{2000}-\frac{1}{1999}-\frac{1}{1998}< 0\)
(b) \(\Leftrightarrow x+2010=0\Leftrightarrow x=-2010\)
a./
\(\Leftrightarrow\frac{x+1}{2}+\frac{x+1}{3}+\frac{x+1}{4}-\frac{x+1}{5}-\frac{x+1}{6}=0.\)
\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}-\frac{1}{5}-\frac{1}{6}\right)=0\)(a)
Mà \(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}-\frac{1}{5}-\frac{1}{6}>0\)
(a) \(\Leftrightarrow x+1=0\Leftrightarrow x=-1\)
c./ \(\Leftrightarrow2\cdot2^2\cdot2^3\cdot...\cdot2^x=2^{10}\Leftrightarrow2^{1+2+3+...+x}=2^{10}\Leftrightarrow1+2+3+...+x=10\)
\(\Leftrightarrow\frac{x\left(x+1\right)}{2}=10\Leftrightarrow x\left(x+1\right)=20=4\cdot5\Rightarrow x=4\)
Bn nào học tốt toán giúp mình mấy bài này nha:
Tính: a)\(\left(\frac{2}{5}\right)^{2014}:\left(\frac{4}{25}\right)^{1007}\) b)\(3^{n+1}:9\)
Tìm x : \(2.2^2.2^3...2^x=1024\)
a)\(\left(\frac{2}{5}\right)^{2014}:\left(\frac{4}{25}\right)^{1007}=\left[\left(\frac{2}{5}\right)^2\right]^{1007}:\left(\frac{4}{25}\right)^{1007}\)
\(=\left(\frac{4}{25}\right)^{1007}:\left(\frac{4}{25}\right)^{1007}\)
\(=1\)
b)\(3^{n+1}:9=3^{n+1}:3^2\)
\(=3^{n+1-2}\)
\(=3^{n-1}\)
Tìm số tự nhiên n biết :
2.22.23......2n=1024
2.22.23....2n = 1024
2.22.23....2n = 210
=> 1+2+3+...+n = 10
(n+1).n : 2 = 10
(n+1).n = 10.2
(n+1).n = 20
(n+1).n = 5.4
=> n = 4
Ta có: \(2.2^2.2^3.....2^n=1024\)
\(\Rightarrow2.2^2.2^3......2^n=2^{10}\)
\(\Rightarrow1+2+3+...+n=10\)
\(\Rightarrow n=4\)
Tìm x
2\(^{^{ }-2}\).2\(^x\)+2.2\(^x\)=9.2\(^6\)
3\(^{-2}\).3\(^4\).3\(^x\)=3\(^7\)
3-2 . 34 . 3x = 37
<=> 32 + x = 37
<=> 2 + x = 7
<=> x = 7 - 2
<=> x = 5
\(2^{-2}\cdot2^x+2\cdot2^x=9\cdot2^6\\ \Rightarrow2^{x-2}+2^{x+1}=9\cdot2^6\\ \Rightarrow2^{x-2}\left(1+2^3\right)=9\cdot2^6\\ \Rightarrow2^{x-2}\cdot9=9\cdot2^6\Rightarrow2^{x-2}=2^6\\ \Rightarrow x-2=6\Rightarrow x=8\)
\(3^{-2}\cdot3^4\cdot3^x=3^7\\ \Rightarrow3^{x+4-2}=3^7\\ \Rightarrow x+2=7\Rightarrow x=5\)
1) \(2^{-2}.2^x+2.2^x=9.2^6\)
\(\Rightarrow2^x.\left(2^{-2}+2\right)=576\)
\(\Rightarrow2^x.\dfrac{9}{4}=576\)
\(\Rightarrow2^x=256=2^8\Rightarrow x=8\)
2) \(\Rightarrow3^{x+2}=3^7\Rightarrow x+2=7\Rightarrow x=5\)
Câu 1 :
a)Tính \(\left(\frac{2}{5}\right)^{2014}:\left(\frac{4}{25}\right)^{1007}\) \(3^{n+1}\): 9 \(\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}}+\left(\frac{50^2-15.125}{5^4}\right)^{2014}\)
b)Tìm x: .\(2.2^2.2^3...2^x=1024\) \(\frac{37-x}{x+13}=\frac{3}{7}\)
giúp mình rồi ai đúng mình tick nhe