\(x^2-0,25=0\)
\(\Leftrightarrow x^2-0,5^2=0\)
\(\Leftrightarrow x-0,5=0\)
\(\Leftrightarrow x=0+0,5\)
\(\Leftrightarrow x=0,5\)
b.
\(\dfrac{8}{2x}=2\Leftrightarrow2x=\dfrac{8}{2}\Rightarrow x=4:2=2\)
c.
\(\left(2x-1\right)^3=8\)
\(\Rightarrow\left(2x-1\right)^3=2^3\)
\(\Rightarrow2x-1=2\)
\(\Rightarrow2x=2+1\)
\(\Rightarrow2x=3\)
\(\Rightarrow x=\dfrac{3}{2}\)
d.
\(\left(x-2\right)^2=16\)
\(\Rightarrow\left(x-2\right)^2=4^2\)
\(\Rightarrow x-2=4\)
\(\Rightarrow x=4+2\)
\(\Rightarrow x=6\)
Chúc bạn học tốt!!!!
\(x^2-0,25=0\)
\(\Rightarrow x^2=0,25\)
\(\Rightarrow x=0,5\)
b. \(\dfrac{8}{2x}=2\)
\(\Rightarrow2x=4\)
\(\Rightarrow x=2\)
c. \(\left(2x-1\right)^3=8\)
\(\left(2x-1\right)^3=2^3\)
\(\Rightarrow2x-1=2\)
\(\Rightarrow x=\dfrac{3}{2}\)
d. \(\left(x-2\right)^2=16\)
\(\left(x-2\right)^2=\pm4^2\)
\(\Rightarrow\left[{}\begin{matrix}x-2=4\\x-2=-4\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)
\(x^2-0,25=0\Rightarrow x^2=0,25\)
\(\Rightarrow\left[{}\begin{matrix}x=0,5\\x=-0,5\end{matrix}\right.\)
\(\dfrac{8}{2x}=2\Rightarrow2x=4\Rightarrow x=2\)
\(\left(2x-1\right)^3=8\)
\(\Rightarrow2x-1=2\Rightarrow2x=3\Rightarrow x=\dfrac{3}{2}\)
\(\left(x-2\right)^2=16\)
\(\Rightarrow\left[{}\begin{matrix}x-2=4\\x-2=-4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)
a, x2 - 0,25 = 0
<=> x2 = 0,25
<=> x2 = (0,5)2
<=> \(\left[{}\begin{matrix}x=0,5\\x=-0,5\end{matrix}\right.\)
b, \(\dfrac{8}{2x}=2\)
<=> 2.2x = 8
<=> 4x = 8
<=> x = 2
c, (2x - 1)3 = 8
<=> (2x - 1)3 = 23
<=> 2x - 1 = 2
<=> 2x = 3
<=> x = \(\dfrac{3}{2}\)
d, (x - 2)2 = 16
<=> (x - 2)2 = 42
<=> \(\left[{}\begin{matrix}x-2=4\\x-2=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)
@Đặng Vũ Hoài Anh
