Question

Answer 1

ảnh lỗi rồi bạn

Answer 2

ảnh vẫn lỗi

Answer 3

\(\Leftrightarrow\left[{}\begin{matrix}7^{5-x}=49=7^2\\\sqrt{x}=2^2=4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}5-x=2\\x=16\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=16\end{matrix}\right.\)

Answer 4

\(c,ĐKXĐ:x\ge0\\ \left(7^{5-x}-49\right)\left(2^2-\sqrt{x}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}7^{5-x}=49\\\sqrt{x}=4\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}5-x=2\\x=16\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=16\left(tm\right)\end{matrix}\right.\)

Answer 5

c) \(\left(7^{5-x}-49\right)\left(2^2-\sqrt{x}\right)=0\)
⇒\(\left[7^{5-x}=49=7^2\right]\)⇒ \(5-x=2\) ⇒ \(x=3\) 
⇒\(\sqrt{x}=2^2=4 \text{⇒} x=16\text{ }\)

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