Giải phương trình :
a, \(\sqrt{x+1}=x-1\)
b, \(x-\sqrt{2x+3}=0\)
c, \(\sqrt{x-2}-3\sqrt{\left(x-2\right)\left(x+2\right)}=0\)
d, \(\sqrt{\sqrt{3}-x}=x\sqrt{\sqrt{3}+x}\)
e, \(2\sqrt{x+3}=9x^2-x-4\)
f, \(\sqrt{x+1}-\sqrt{x-7}=\sqrt{12-x}\)
g, \(\sqrt{2x+5}-\sqrt{3x-5}=2\)
h, \(\sqrt{x}-\sqrt{x-1}-\sqrt{x-4}+\sqrt{x+9}=0\)
i, \(x^2+2x-\sqrt{x^2+2x+1}-5=0\)
k, \(\sqrt{x+8-6\sqrt{x+1}}=4\)
l, \(\sqrt{x^2-8x+16}+\sqrt{x^2-10x+25}=9\)
Làm được phần nào thì giúp mình nha đang cần gấp !!!
I) xd mọi x
\(\sqrt{x^2-8x+16}+\sqrt{x^2-10x+25}=9\)
\(\sqrt{\left(x-4\right)^2}+\sqrt{\left(x-5\right)^2}=9=>\left|x-4\right|+\left|x-5\right|=9\)
\(\left[{}\begin{matrix}x< 4\Rightarrow4-x+5-x=>x=0\left(n\right)\\4\le x< 5\Rightarrow x-4+5-x=9\left(vn\right)\\x\ge5\Rightarrow x-4+x-5=9\Rightarrow x=9\left(n\right)\\\end{matrix}\right.\)
kết luận
\(\left[{}\begin{matrix}x=0\\x=9\end{matrix}\right.\)
