Question

[Ran]

Làm hộ mk bài dưới với!

Answer 1

[๖ۣۜᛕᕼôᑎǤ×͜×ᗪᗩᑎᕼ°ᵒ彡『ʈєɑɱ❖๖ۣۜƝƘ☆』]

\(|x^2+4|=4x\)

\(\Leftrightarrow\orbr{\begin{cases}x^2+4=4x\\x^2+4=-4x\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x^2-4x+4=0\\x^2+4x+4=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}\left(x-2\right)^2=0\\\left(x+2\right)^2=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x-2=0\\x+2=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=-2\end{cases}}\)

VẬy x = 2 hoặc x = -2

Answer 2

[Quỳnh Anh]

Trả lời:

a, \(\left|x^2+4\right|=4x\) \(\left(ĐK:x\ge0\right)\)

+) TH1: \(x^2+4=4x\Leftrightarrow x^2-4x+4=0\Leftrightarrow\left(x-2\right)^2=0\Leftrightarrow x-2=0\Leftrightarrow x=2\)(tm)

+) TH2: \(x^2+4=-4x\Leftrightarrow x^2+4x+4=0\Leftrightarrow\left(x+2\right)^2=0\Leftrightarrow x+2=0\Leftrightarrow x=-2\)(ktm)

Vậy x = 2

b, \(\left|2-4x\right|=2x+1\) \(\left(ĐK:x\ge-\frac{1}{2}\right)\)

+) TH1: \(2-4x=2x+1\Leftrightarrow6x-1=0\Leftrightarrow x=\frac{1}{6}\) (tm)

+) TH2: \(2-4x=-2x-1\Leftrightarrow2x-3=0\Leftrightarrow x=\frac{3}{2}\) (tm)

Vậy x = 1/6; x = 3/2