2x+2x+1+2x+2+...+2x+2020=2x+2024-8
(2x-1)/2020+(2x-3)/2024= (1-2 x)/1008
a) 5(x-2)(x+3)=1
b) 7(x-2024)2 = 23- y2
c) |x2+ 2x| + |y2- 9|= 0
d) 2x+ 2x+1+2x+2+2x+3=120
e) ( x- 7 )x+1- (x - 7)x+11=0
f) 25 - y2= 8(x 2012)2
a: \(5^{\left(x-2\right)\left(x+3\right)}=1\)
=>\(\left(x-2\right)\left(x+3\right)=0\)
=>\(\left[{}\begin{matrix}x-2=0\\x+3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)
c: \(\left|x^2+2x\right|+\left|y^2-9\right|=0\)
mà \(\left\{{}\begin{matrix}\left|x^2+2x\right|>=0\forall x\\\left|y^2-9\right|>=0\forall y\end{matrix}\right.\)
nên \(\left\{{}\begin{matrix}x^2+2x=0\\y^2-9=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\left(x+2\right)=0\\\left(y-3\right)\left(y+3\right)=0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x\in\left\{0;-2\right\}\\y\in\left\{3;-3\right\}\end{matrix}\right.\)
d: \(2^x+2^{x+1}+2^{x+2}+2^{x+3}=120\)
=>\(2^x\left(1+2+2^2+2^3\right)=120\)
=>\(2^x\cdot15=120\)
=>\(2^x=8\)
=>x=3
e: \(\left(x-7\right)^{x+1}-\left(x-7\right)^{x+11}=0\)
=>\(\left(x-7\right)^{x+11}-\left(x-7\right)^{x+1}=0\)
=>\(\left(x-7\right)^{x+1}\left[\left(x-7\right)^{10}-1\right]=0\)
=>\(\left[{}\begin{matrix}x-7=0\\x-7=1\\x-7=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=8\\x=6\end{matrix}\right.\)
Tìm số nguyên x biết: 2x+2x+1+2x+2+…+2x+2020=22024-8
Lời giải:
$2^x+2^{x+1}+2^{x+2}+...+2^{x+2020}=2^{2024}-8$
$2^x(1+2+2^2+...+2^{2020})=2^{2024}-8(1)$
$2^x(2+2^2+2^3+...+2^{2021})=2^{2025}-16(2)$
Lấy $(2)$ trừ $(1)$ ta có:
$2^x(2^{2021}-1)=2^{2025}-16-(2^{2024}-8)=2^{2024}(2-1)-8$
$2^x(2^{2021}-1)=2^{2024}-8=2^3(2^{2021}-1)$
$\Rightarrow 2^x=2^3$
$\Rightarrow x=3$
a,4.|3x-1|=|6x-2|+|-1,5|
b,2024.|2x-1|=2025.|1-2x|-|-2|
c,|2x+1|+|3x-1|=0
c, |2\(x\) + 1| + |3\(x\) - 1| = 0
vì |2\(x\) + 1| ≥ 0; |3\(x\) - 1| = 0
⇒ |2\(x\) + 1| + |3\(x\) - 1| = 0
⇔ \(\left\{{}\begin{matrix}2x+1=0\\3x-1=0\end{matrix}\right.\)
⇔ \(\left\{{}\begin{matrix}2x=-1\\3x=1\end{matrix}\right.\)
\(\Rightarrow\) \(\left\{{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)
\(-\dfrac{1}{2}\) < \(\dfrac{1}{3}\)
Vậy \(x\) \(\in\) \(\varnothing\)
a, Nếu 4.|3\(x\) - 1| = |6\(x\) - 2| + |-1,5|
4.|3\(x\) -1| - 2.|3\(x\) - 1| = 1,5
Nếu 3\(x\) - 1 ≥ 0 ⇒ \(x\) ≥ \(\dfrac{1}{3}\)
Ta có: 4.(3\(x\) - 1) - 2.(3\(x\) - 1) = 1,5
12\(x\) - 4 - 6\(x\) + 2 = 1,5
6\(x\) - 2 = 1,5
6\(x\) = 1,5 + 2
6\(x\) = 3,5
\(x\) = 3,5: 6
\(x\) = \(\dfrac{7}{12}\)
Nếu 3\(x\) - 1 < 0 ⇒ \(x\) < \(\dfrac{1}{3}\)
Ta có: - 4.(3\(x\) - 1) = - (6\(x\) - 2) + 1,5
-12\(x\) + 4 + 6\(x\) - 2 = 1,5
-6\(x\) + 2 = 1,5
6\(x\) = 2- 1,5
6\(x\) = 0,5
\(x\) = 0,5 : 6
\(x\) = \(\dfrac{1}{12}\)
Vậy \(x\) \(\in\) {\(\dfrac{1}{12}\); \(\dfrac{7}{12}\)}
b, 2024.|2\(x\) - 1| = 2025.|1 - 2\(x\)| - |-2|
2025.|1 - 2\(x\)| - 2024.|1 - 2\(x\)| = |-2|
|1 - 2\(x\)| = 2
Nếu 1 - 2\(x\) ≥ 0 ⇒ \(x\) ≥ \(\dfrac{1}{2}\)
với \(x\) ≥ \(\dfrac{1}{2}\) ta có: 1 - 2\(x\) = 2 ⇒ 2\(x\) = -1 ⇒ \(x\) = - \(\dfrac{1}{2}\) (1)
Nếu \(1-2x\) < 0 ⇒ 2\(x\) ≤ 1 ⇒ \(x\) < \(\dfrac{1}{2}\)
Với \(x\) < \(\dfrac{1}{2}\) ta có: -1 + 2\(x\) = 2 ⇒ 2\(x\) = 3 ⇒ \(x\) = \(\dfrac{3}{2}\) (2)
Kết hợp(1) và (2) ta có: \(x\) \(\in\) { - \(\dfrac{1}{2}\); \(\dfrac{3}{2}\)}
tìm x,y biết (2x-7)^2020+(y^2-9)^2024+(x-y)^2030=0
Tính giá trị của biểu thức \(B=\dfrac{4x^{2024}\left(x+1\right)-2x^{2023}+2x+1}{2x^2+3x}\) tại \(x=\sqrt{\dfrac{1}{2\sqrt{3}}-\dfrac{3}{2\sqrt{3}+2}}\)
\(x=\sqrt{\dfrac{2\sqrt{3}+2-6\sqrt{3}}{2\sqrt{3}\left(2\sqrt{3}+2\right)}}=\sqrt{\dfrac{2-4\sqrt{3}}{2\sqrt{3}\left(2\sqrt{3}+2\right)}}\) ko tồn tại vì 2-4căn 3<0
Tìm GTLN:
a. A=\(\frac{2020}{\left(x+3\right)^2+\left|y+1\right|+5}\)
b. B= -x2 - 2x +8
c. C= \(\frac{x^2-2x+2020}{x^2-2x+2020}\)
cho \(\sqrt{2020-3x+2x^2}-\sqrt{4-3x+2x^2}=1\)
tính \(\sqrt{2020-3x+2x^2}+\sqrt{4-3x+2x^2}\)
X^2+x=2020
Tính x^6+2x^5+2x^4+2x^3+2x^2+401x+1
Giúp mình nhé!