\(\left(x-5\right)^4.|y^2-25|=0\)

\(\Rightarrow\left[{}\begin{matrix}\left(x-5\right)^4=0\\|y^2-25|=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x-5=0\\y^2-25=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0+5=5\\y^2=0+25=25\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=5\\y=5;-5\end{matrix}\right.\)

Vậy x=5 và y=5;-5

Cảm mơn nha

5: \(=-\left(x^2+3x+5\right)\)

\(=-\left(x^2+3x+\dfrac{9}{4}+\dfrac{11}{4}\right)\)

\(=-\left(x+\dfrac{3}{2}\right)^2-\dfrac{11}{4}< 0\)

6: \(=-3\left(x^2+2x+\dfrac{4}{3}\right)=-3\left(x^2+2x+1+\dfrac{1}{3}\right)\)

\(=-3\left(x+1\right)^2-1< 0\)

\(H=4x^2+4x+2=\left(2x+1\right)^2+1>0\)

\(K=4x^2+3x+2=4\left(x^2+2.\frac{3}{8}x+\frac{9}{64}\right)+\frac{23}{16}\)

      \(=4\left(x+\frac{3}{8}\right)^2+\frac{23}{16}>0\)

\(L=2x^2+3x+4=2\left(x^2+2.\frac{3}{4}x+\frac{9}{16}\right)+\frac{23}{8}\)

      \(=2\left(x+\frac{3}{4}\right)^2+\frac{23}{8}>0\)

Bạn viết rõ ra câu h đc ko giúp nha thanks bạn nhiều Đườnh Quỳnh Giang 

Có   \(\left(x-5\right)^2=\left(1-3x\right)^2\)

\(\Leftrightarrow x-5=1-3x\)

\(\Leftrightarrow x+3x=1+5\)

\(\Leftrightarrow4x=6\)

\(\Leftrightarrow x=6:4\)

\(\Leftrightarrow x=\frac{3}{2}\)

\(\left|-2\right|\cdot3^x+3^{x+2}=99\)

\(\Rightarrow2\cdot3^x+3^x\cdot3^2=99\)

\(\Rightarrow3^x\cdot\left(2+3^2\right)=99\)

\(\Rightarrow3^x\cdot11=99\)

\(\Rightarrow3^x=99:11\)

\(\Rightarrow3^x=9\)

\(\Rightarrow3^x=3^2\)

\(\Rightarrow x=2\)