\(\left(3-4x\right)^2=25=5^2\)
\(\Rightarrow3-4x=5\)
\(\Rightarrow4x=3-5=-2\Rightarrow x=-\frac{1}{2}\)
\(\left(2x-\frac{1}{4}\right)^2=16=4^2\)
\(\Rightarrow2x-\frac{1}{4}=4\Rightarrow2x=4+\frac{1}{4}=\frac{17}{4}\)
\(\Rightarrow x=\frac{17}{4}:2=\frac{17}{4}.\frac{1}{2}=\frac{17}{8}\)
Đề số 3 bị sai.
\(\left(2x+5\right)^2=0\Rightarrow2x+5=0\Rightarrow2x=-5\Rightarrow x=-\frac{5}{2}\)
(3-4x)2=25
3-4x=5
4x=3-5
4x=-2
x=-2:4
x=-0,5
b)(2x-1/42)=16
2x-1/4=4
2x=4+1/4
2x=4,25
x=2,125
c) cái này x ở đâu vậy bn
d) (2x+5)2=0
2x+5=0
2x=0+5
2x=5
x=5:2
x=5/2
Nhớ k cho mk nha
a)\(\left(3-4x\right)^2=25\)
\(\Rightarrow\orbr{\begin{cases}3-4x=5\\3-4x=-5\end{cases}}\Rightarrow\orbr{\begin{cases}4x=3-5\\4x=3-\left(-5\right)\end{cases}}\Rightarrow\orbr{\begin{cases}4x=-2\\4x=8\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{-1}{2}\\x=2\end{cases}}\)
b) \(\left(2x-\frac{1}{4}\right)^2=16\)
\(\Rightarrow\orbr{\begin{cases}2x-\frac{1}{4}=4\\2x-\frac{1}{4}=-4\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}2x=-4+\frac{1}{4}\\2x=4+\frac{1}{4}\end{cases}}\Leftrightarrow\orbr{\begin{cases}2x=-\frac{15}{4}\\2x=\frac{17}{4}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{-15}{4}:2\\x=\frac{17}{4}:2\end{cases}}\Rightarrow\orbr{\begin{cases}x=-\frac{15}{8}\\x=\frac{17}{8}\end{cases}}\)
c)\(\left(4-x\right)^2=16\)
\(\Rightarrow\orbr{\begin{cases}4-x=4\\4-x=-4\end{cases}}\Rightarrow\orbr{\begin{cases}x=4-4\\x=4-\left(-4\right)\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x=8\end{cases}}\)
d) \(\left(2x+5\right)^2=0\)
\(\Rightarrow2x+5=0\Rightarrow2x=-5\Rightarrow x=\frac{-5}{2}\)
\(\left(3-4x\right)^2=25\)
\(\Leftrightarrow\left(3-4x\right)^2=5^2\)
\(\Leftrightarrow\orbr{\begin{cases}3-4x=5\\3-4x=-5\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-\frac{1}{2}\\x=2\end{cases}}}\)
