2x+2x+1=48
2 x - 2 - 2 x + 1 . x 2 + 4 x + 4 8
Tìm x, biết :
2x-1 + 2x = 48
\(2^{x-1}+2^x=48\)
\(\Rightarrow2^x\cdot\dfrac{1}{2}+2^x=48\)
\(\Rightarrow2^x\left(\dfrac{1}{2}+1\right)=48\)
\(\Rightarrow2^x\cdot\dfrac{3}{2}=48\)
\(\Rightarrow2^x=32\)
\(\Rightarrow x=5\)
Vậy x = 5
#gboy2mai
Bài 1 :
a, x = 3y = 2z và 2x - 3y + 4z = 48
b, 2x = 3y = -2z và 2x - 3y + 4z = 48
CÍU EM VS !
Tìm x:
2^2x + 2^2x+1 = 48
\(2^{2x}+2^{2x+1}=48\)
\(2^{2x}+2^{2x}.2=48\)
\(2^{2x}.\left(1+2\right)=48\)
\(2^{2x}.3=48\)
\(2^{2x}=48:3\)
\(2^{2x}=16\)
\(2^{2x}=2^4\)
\(\Rightarrow2x=4\)
\(x=4:2\)
\(x=2\)
\(2^{2x}+2^{2x+1}=48\\ \Rightarrow2^{2x}+2.2^{2x}=48\\ \Rightarrow\left(1+2\right).2^{2x}=48\\ \Leftrightarrow3.2^{2x}=48\\ \Leftrightarrow2^{2x}=16\\ \Leftrightarrow2^{2x}=2^4\\ \Leftrightarrow2x=4\\ \Leftrightarrow x=2\)
Vậy x = 2
tìm x.y là stn a) (2x-1)(5y+1) = 30 b) (2x + 1)(y-2)=48
Tìm x, biết:
4 * 2^x42 - 2x = 480
(2x^2 + 1)*(x-3)=0
48-(15-x)^5=48
(2x2 + 1)(x-3)=0
\(\Rightarrow\orbr{\begin{cases}2x^2+1=0\\x-3=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}2x^2=-1\Rightarrow x^2=-\frac{1}{2}\left(vl\right)\\x=3\end{cases}}\)
Vậy x=3
48-(15-x)5=48
(15-x)5=48-48
(15-x)5=0
=> 15-x =0
x =15-0
x =15
Vậy x=15
Tìm x:
a) x(2-x)+(x2+x)=7
b) (2x+1)2-x(4-5x)=17
c) (4-x)2-(2x+1)2=0
d) (2x3-8x2+10x) : (2x)=0
e) (4x4-16x-48) : (-2x)2=0
a: Ta có: \(x\left(2-x\right)+\left(x^2+x\right)=7\)
\(\Leftrightarrow2x-x^2+x^2+x=7\)
\(\Leftrightarrow3x=7\)
hay \(x=\dfrac{7}{3}\)
b: Ta có: \(\left(2x+1\right)^2-x\left(4-5x\right)=17\)
\(\Leftrightarrow4x^2+4x+1-4x+5x^2=17\)
\(\Leftrightarrow9x^2=16\)
\(\Leftrightarrow x^2=\dfrac{16}{9}\)
hay \(x\in\left\{\dfrac{4}{3};-\dfrac{4}{3}\right\}\)
c: Ta có: \(\left(x-4\right)^2-\left(2x+1\right)^2=0\)
\(\Leftrightarrow\left(x-4-2x-1\right)\left(x-4+2x+1\right)=0\)
\(\Leftrightarrow\left(x+5\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=1\end{matrix}\right.\)
d: ta có: \(\dfrac{2x^3-8x^2+10x}{2x}=0\)
\(\Leftrightarrow x^2-4x+5=0\)
\(\Leftrightarrow\left(x-2\right)^2+1=0\)(vô lý)
Tìm x biết
\(\dfrac{2x-1}{-12}\)=\(\dfrac{48}{1-2x}\)
Giúp mình vs ạ, mình cảm ơn nhiều
=>(2x-1)^2=24^2
=>2x-1=24 hoặc 2x-1=-24
=>x=-23/2 hoặc x=25/2
\(\dfrac{2x-1}{-12}=\dfrac{48}{1-2x}\) (ĐK: \(x\ne\dfrac{1}{2}\))
\(\Leftrightarrow\dfrac{2x-1}{12}=\dfrac{48}{2x-1}\)
\(\Leftrightarrow-12\cdot48=\left(2x-1\right)\left(2x-1\right)\)
\(\Leftrightarrow567=\left(2x-1\right)^2\)
\(\Leftrightarrow24^2=\left(2x-1\right)^2\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1=-24\\2x-1=24\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=-23\\2x=25\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{23}{2}\left(tm\right)\\x=\dfrac{25}{2}\left(tm\right)\end{matrix}\right.\)
Tìm x, biết:
\(\dfrac{1}{2.4}+\dfrac{1}{4.6}+...+\dfrac{1}{\left(2x-2\right).2x}=\dfrac{11}{48}\) (x ϵ N , x ≥ 2)
\(\Leftrightarrow\dfrac{2}{2.4}+\dfrac{2}{4.6}+...+\dfrac{2}{\left(2x-2\right).2x}=\dfrac{11}{24}\)
\(\Leftrightarrow\dfrac{4-2}{2.4}+\dfrac{6-4}{4.6}+...+\dfrac{2x-\left(2x-2\right)}{\left(2x-2\right).2x}=\dfrac{11}{24}\)
\(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+...+\dfrac{1}{2x-2}-\dfrac{1}{2x}=\dfrac{11}{24}\)
\(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{2x}=\dfrac{11}{24}\)
\(\Leftrightarrow\dfrac{1}{2x}=\dfrac{1}{2}-\dfrac{11}{24}\)
\(\Leftrightarrow\dfrac{1}{2x}=\dfrac{1}{24}\)
\(\Rightarrow2x=24\)
\(\Rightarrow x=12\)
(x-3).45=48
2x+1-1=63
\(2^{x+1}-1=63\\ 2^{x+1}=64\\ 2^{x+1}=2^6\\ =>X+1=6\\ =>x=5\)
\(\left(X-3\right)\cdot4^5=4^8\\ X-3=64\\ =>X=67\)