(4x-1)30 =(4x-1)20
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ta có : \(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)(=)\(\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)(=)\(\left(4x-1\right)^{20}\left[\left(4x-1\right)^{10}-1\right]=0\)(=)\(\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left[\left(4x-1\right)^{10}-1\right]=0\end{cases}}\)(=)\(\orbr{\begin{cases}4x-1=0\\\left(4x-1\right)^{10}=1\end{cases}}\)(=)\(\orbr{\begin{cases}4x=1\\\begin{cases}4x-1=1\\4x-1=-1\end{cases}\end{cases}}\)(=)\(\orbr{\begin{cases}x=\frac{1}{3}\\\begin{cases}4x=2\\4x=0\end{cases}\end{cases}}\)\(\orbr{\begin{cases}x=\frac{1}{4}\\\begin{cases}x=\frac{1}{2}\\x=0\end{cases}\end{cases}}\)
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(4x^{30}-1^{30}=4x^{20}-1^{20}\)
\(4x^{30}-4x^{20}=-1+1\)
\(4x^{20}\left(x^{10}-1\right)=0\)
\(\Rightarrow\orbr{\begin{cases}4x^{20}=0\\x^{10}-1=0\end{cases}\Rightarrow\orbr{\begin{cases}x^{20}=0\\x^{10}=1\end{cases}\Rightarrow}\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}}\)
hok tốt!!
Ta có \(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
<=> \(\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
<=> \(\left(4x-1\right)^{20}.\left[\left(4x-1\right)^{10}-1\right]=0\)
<=> \(\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x-1=0\\\left(4x-1\right)^{10}=1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x=1\\4x-1=1;4x-1=-1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{4}\\4x=2;4x=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{4}\\x=2;x=0\end{cases}}\)
Vậy \(x\in\left\{0;2;\frac{1}{4}\right\}\)
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Hc tốt
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(\Leftrightarrow\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
\(\Leftrightarrow\left(4x-1\right)^{20}\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x-1=0\\\left(4x-1\right)^{10}=1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x=1\\4x-1=-1;1\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=\frac{1}{4}\\x=0\\x=\frac{1}{2}\end{cases}}\)
Vậy \(x=\frac{1}{4};0;\frac{1}{2}\)
P/s : phần \(\Leftrightarrow\hept{\begin{cases}x=\frac{1}{4}\\x=0\\x=\frac{1}{2}\end{cases}}\) thay dấu \(\hept{\begin{cases}\\\\\end{cases}}\) thành dấu \(\orbr{\begin{cases}\\\end{cases}}\) nhé!
\(\Leftrightarrow\orbr{\begin{cases}4x=1\\4x-1=\pm1\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{4}\\\orbr{\begin{cases}x=0\\x=\frac{1}{2}\end{cases}}\end{cases}}\)
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(\Leftrightarrow\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
\(\Leftrightarrow\left(4x-1\right)^{20}.\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}4x-1=0\\\left(4x-1\right)^{10}=1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{4}\\4x-1=\pm1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=0\end{cases}}\)
Vậy x = 1/4 hoặc 1/2 hoặc 0
Ta có:
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
Xét \(4x-1=0\)
\(\Rightarrow4x=1\Rightarrow x=\frac{1}{4}\), thỏa mãn
Xét \(4x-1\ne0\)
\(\Rightarrow\left(4x-1\right)^{30}:\left(4x-1\right)^{20}=1\)
\(\Rightarrow\left(4x-1\right)^{10}=1\Rightarrow\left[{}\begin{matrix}4x-1=1\Rightarrow x=\frac{1}{2}\\4x-1=-1\Rightarrow x=0\end{matrix}\right.\)
Vậy....
Ta có: \(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(\Rightarrow\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
\(\Rightarrow\left(4x-1\right)^{20}.\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(4x-1\right)^{20}=0\\\left[\left(4x-1\right)^{10}-1\right]=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}4x-1=0\\\left(4x-1\right)^{10}=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}4x=1\\4x-1=1\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{1}{4}\\4x=2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\frac{1}{4}\\x=\frac{2}{4}=\frac{1}{2}\end{matrix}\right.\)
Vậy: \(x\in\left\{\frac{1}{2};\frac{1}{4}\right\}\)
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(\Rightarrow\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
\(\Rightarrow\left(4x-1\right)^{20}.\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}4x-1=0\\\left(4x-1\right)^{10}=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}4x=1\\4x-1=1\\4x-1=-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\frac{1}{4}\\4x=2\\4x=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{1}{4}\\x=\frac{1}{2}\\x=0\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{1}{4};\frac{1}{2};0\right\}.\)
Chúc bạn học tốt!
mình biết nè giải như sau
[4x-1]^30=[4x-1]^20
[4x-1]^30-[4x-1]^20=0 ....
còn lại bạn tự giải nhé
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
=> \(\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
=> \(\left(4x-1\right)^{20}.\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Rightarrow\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}4x-1=0\\\left(4x-1\right)^{10}=1\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}4x=1\\4x-1\in\left\{\pm1\right\}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=1\\4x\in\left\{0;2\right\}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=1\\x\in\left\{0;\frac{1}{2}\right\}\end{cases}}\)
Vậy ...
Học tốt
a) 72,5 - (2x + 1) = 630 : 9
⇒ 72,5 - (2x + 1) = 70
⇒ 2x + 1 = 2,5
⇒ 2x = 1,5
⇒ x = 0,75
b) (10 - 4x) + 120 : 23 = 17
⇒ (10 - 4x) + 120 : 8 = 17
⇒ (10 - 4x) + 15 = 17
⇒ 10 - 4x = 2
⇒ 4x = 8
⇒ x = 2
Vậy x = 2
ĐKXĐ: \(x\ne\pm\frac{3}{2}\)
\(\frac{1}{\left(2x-3\right)^2}+\frac{3}{\left(2x-3\right)\left(2x+3\right)}-\frac{4}{\left(2x+3\right)^2}=0\)
\(\Leftrightarrow\frac{1}{\left(2x-3\right)^2}-\frac{1}{\left(2x-3\right)\left(2x+3\right)}+\frac{4}{\left(2x-3\right)\left(2x+3\right)}-\frac{4}{\left(2x-3\right)^2}=0\)
\(\Leftrightarrow\frac{1}{2x-3}\left(\frac{1}{2x-3}-\frac{1}{2x+3}\right)-\frac{4}{2x-3}\left(\frac{1}{2x-3}-\frac{1}{2x+3}\right)=0\)
\(\Leftrightarrow\left(\frac{1}{2x-3}-\frac{4}{2x+3}\right)\left(\frac{1}{2x-3}-\frac{1}{2x+3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+3=2x-3\left(vn\right)\\2x+3=4\left(2x-3\right)\Rightarrow x=\frac{5}{2}\end{matrix}\right.\)
\(\left(4x-1\right)^{30}=\left(4x-1\right)^{20}\)
\(\Leftrightarrow\left(4x-1\right)^{30}-\left(4x-1\right)^{20}=0\)
\(\Leftrightarrow\left(4x-1\right)^{20}\left[\left(4x-1\right)^{10}-1\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(4x-1\right)^{20}=0\\\left(4x-1\right)^{10}-1=0\end{cases}}\)
*Với \(\left(4x-1\right)^{20}=0\)
\(\Rightarrow4x-1=0\)
\(\Rightarrow x=\frac{1}{4}\)
*Với \(\left(4x-1\right)^{20}-1=0\)
\(\Rightarrow\left(4x-1\right)^{20}=1\)
\(\Rightarrow\orbr{\begin{cases}4x-1=1\\4x-1=-1\end{cases}\Leftrightarrow\orbr{\begin{cases}4x=2\\4x=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{1}{2}\\x=0\end{cases}}}\)
Vậy \(x\in\left\{0;\frac{1}{4};\frac{1}{2}\right\}\)