Question

GIẢI PT:

(1/x^2-5x+6)+(!/x^2-7x+12)+(1/x^2-9x+20)+(1/x^2-11x+30)=1/8

Answer 1

Đk:\(x\ne2;x\ne3;x\ne4;x\ne5;x\ne6\)

\(pt\Leftrightarrow\frac{1}{\left(x-6\right)\left(x-5\right)}+\frac{1}{\left(x-5\right)\left(x-4\right)}+...+\frac{1}{\left(x-3\right)\left(x-2\right)}=\frac{1}{8}\)

\(\Leftrightarrow\frac{1}{x-6}-\frac{1}{x-5}+\frac{1}{x-5}-\frac{1}{x-4}+\frac{1}{x-4}+...+\frac{1}{x-3}-\frac{1}{x-2}=\frac{1}{8}\)

\(\Leftrightarrow\frac{1}{x-6}-\frac{1}{x-2}=\frac{1}{8}\)\(\Leftrightarrow\frac{x-2}{\left(x-6\right)\left(x-2\right)}-\frac{x-6}{\left(x-2\right)\left(x-6\right)}=\frac{1}{8}\)

\(\Leftrightarrow\frac{4}{\left(x-6\right)\left(x-2\right)}=\frac{1}{8}\Leftrightarrow\left(x-2\right)\left(x-6\right)=32\)

\(\Leftrightarrow x^2-8x+12=32\Leftrightarrow x^2-8x-20=0\)

\(\Leftrightarrow\left(x-10\right)\left(x+2\right)=0\)\(\Leftrightarrow\orbr{\begin{cases}x=10\\x=-2\end{cases}}\)

Answer 2

! là gì vậy bn sao ghi vào?

Answer 3

giải phuong trinh a bn

Answer 4

nhưng cái thứ hai tử là ! nghĩa là gì?

Answer 5

là số 1