`\sqrt{4x^2 +5x+1}-9x=2\sqrt{x^2 -x+1}-3`

`->` làm đầy đủ nha

$\begin{cases}\dfrac{96}{x+y}+\dfrac{96}{x-y}=14 \\\dfrac{96}{x+y}+\dfrac{72}{x-y}=\dfrac{24}{y} \end{cases}$

Giai chi tiết nha!!!!!!!!!!!!!!

a.\(\left\{{}\begin{matrix}\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{1}{6}\\\dfrac{8}{x}+\dfrac{5}{y}=1\end{matrix}\right.\)

\(ĐK:x;y\ne0\)

Đặt \(\left\{{}\begin{matrix}\dfrac{1}{x}=a\\\dfrac{1}{y}=b\end{matrix}\right.\) 

hpt trở thành:

\(\left\{{}\begin{matrix}a+b=\dfrac{1}{6}\\8a+5b=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=\dfrac{1}{18}\\b=\dfrac{1}{9}\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\dfrac{1}{x}=\dfrac{1}{18}\\\dfrac{1}{y}=\dfrac{1}{9}\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=18\\y=9\end{matrix}\right.\) ( tm )

Vậy nghiệm hpt: \(\left\{{}\begin{matrix}x=18\\y=9\end{matrix}\right.\)

b.\(\left\{{}\begin{matrix}\dfrac{x-1}{2}-y=1\\2x+y=1\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x-1}{2}+2x=2\\2x+y=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x-1+4x}{2}=\dfrac{4}{2}\\2x+y=1\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}5x=5\\2x+y=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=1\\2.1+y=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=-1\end{matrix}\right.\)

`(x:1/4+3/2)*2/7=(-1)/7`

`12+90+34+5-69+56+3+45+38+129+369+3`

Tình hợp lí

Tìm tất cả tham số `m` để bất phương trình `x^2-x+m(1-m)<=0` là hệ quả của bất phương trình `\sqrt{\sqrt{x-1}+4}-\sqrt{\sqrt{x-1}+1}>=1`?
`A.m=1/2`
`B.m<=0` hoặc `m>=1`
`C.m>=1`
`D.m<=0`

`3/5 xx x=4/7`

`=>x=4/7 :3/5`

`=>x=(20)/(21)`

Vậy `x=(20)/(21)`