\(\frac{1}{\sqrt{2}}\)+\(\frac{1}{\sqrt{3}}\)
K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

8 tháng 8 2017

\(\Leftrightarrow\sqrt{4-\left(1-x\right)^2}=\sqrt{3}\)

\(\Leftrightarrow4-\left(1-x\right)^2=3\)

\(\Leftrightarrow4-\left(1-2x+x^2\right)-3=0\)

\(\Leftrightarrow4-1+2x-x^2-3=0\)

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

vay x=0 ; x=2

\(\sqrt{3x^2-5=2}\left(x\ge\sqrt{\frac{5}{3}}\right)\)

\(\Leftrightarrow3x^2-5=4\)

\(\Leftrightarrow3x^2=9\Leftrightarrow x^2=3\Leftrightarrow\orbr{\begin{cases}x=\sqrt{3}\left(tm\right)\\x=-\sqrt{3}\left(kotm\right)\end{cases}}\)

vay \(x=\sqrt{3}\)

\(\sqrt{\left(\sqrt{x}-7\right)\left(\sqrt{x}+7\right)}=2\left(x\ge49\right)\)

\(\Leftrightarrow\sqrt{x-49}=2\Leftrightarrow x^2-98x+2401=4\)

\(\Leftrightarrow x^2-98x+2397=0\Leftrightarrow x^2-47x-51x+2397\)\(\Leftrightarrow x\left(x-47\right)-51\left(x-47\right)\Leftrightarrow\left(x-47\right)\left(x-51\right)\)

\(\Leftrightarrow\orbr{\begin{cases}x-51=0\\x-47=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=51\left(tm\right)\\x=47\left(kotm\right)\end{cases}}}\)

xay x=51

\(\sqrt{\frac{-6}{1+x}}=5\left(x< -1\right)\)

\(\Leftrightarrow\frac{36}{x^2+2x+1}=25\Leftrightarrow25x^2+50x+25=36\)

\(\Leftrightarrow25x^2+50x-11=0\Leftrightarrow25x^2-5x+55x-11\)

\(\Leftrightarrow5x\left(5x-1\right)+11\left(5x-1\right)\Leftrightarrow\left(5x-1\right)\left(5x+11\right)\)\(\Leftrightarrow\orbr{\begin{cases}5x-1=0\\5x+11=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{5}\left(kotm\right)\\x=\frac{-11}{5}\left(tm\right)\end{cases}}}\)

vay \(x=\frac{-11}{5}\)

nhung cau nay binh phuong len la xong 

y 3 xem lai de bai 

y 4,7 ko biet lam