a) \(\dfrac{1997x1996-1}{1995x1997+1996}=\dfrac{1997x\left(1995+1\right)-1}{1995x1997+1996}\)

\(=\dfrac{1997x1995+1997-1}{1995x1997+1996}=\dfrac{1997x1995+1996}{1995x1997+1996}=1\)

b) \(\dfrac{1997x1996-995}{1995x1997+1002}=\dfrac{1997x\left(1995+1\right)-995}{1995x1997+1002}\)

\(=\dfrac{1997x1995+1997-995}{1995x1997+1002}=\dfrac{1997x1995+1002}{1995x1997+1002}=1\)

\(...=\dfrac{1998x1996+1996+1+1996-1}{\left(1997-1995\right)x1996}\)

\(=\dfrac{1998x1996+2x1996}{2x1996}=\dfrac{1996\left(1998+2\right)}{2x1996}=\dfrac{2000}{2}=1000\)

KQ = 995 nha

cộng 1 vào mỗi tỉ số,ta đc:

(x+5)/1995+1+(x+4)/1996+1+(x+3)/1997+1=(x+1995)/5+1+(x+1996)/4+1+(x+1997|/3+1

=>\(\frac{x+5+1995}{1995}+\frac{x+4+1996}{1996}+\frac{x+3+1997}{1997}=\frac{x+1995+5}{5}+\frac{x+1996+4}{4}+\frac{x+1997+3}{3}\)

\(\Rightarrow\frac{x+2000}{1995}+\frac{x+2000}{1996}+\frac{x+2000}{1997}-\frac{x+2000}{5}-\frac{x+2000}{4}-\frac{x-2000}{3}=0\)

\(\Rightarrow\left(x+2000\right)\left(\frac{1}{1995}+\frac{1}{1996}+\frac{1}{1997}-\frac{1}{5}-\frac{1}{4}-\frac{1}{3}\right)=0\)

mà bt trong ngoặc thứ 2 khác 0

=>x+2000=0

=>x=-2000

\(\dfrac{1997\times1996-1}{1995\times1997+1996}\)

= \(\dfrac{1997\times\left(1995+1\right)-1}{1995\times1997+1996}\)

= \(\dfrac{1997\times1995+1997-1}{1995\times1997+1996}\)

= \(\dfrac{1995\times1997+1996}{1995\times1997+1996}\)

= 1

Trả lời :

\(\frac{1998\times1996+1997\times11+1985}{1997\times1996-1995\times1996}\)

\(=\frac{1998\times1996+\left(1996+1\right)\times11+1985}{1996\times\left(1997-1995\right)}\)

\(=\frac{1998\times1996+1996\times11+11+1985}{1996\times2}\)

\(=\frac{1998\times1996+1996\times11+1996}{1996\times2}\)

\(=\frac{1996\times\left(1998+11+1\right)}{1996\times2}\)

\(=\frac{2010}{2}\)

\(=1005\)

tự nhiên -1997*1996+1/-1995*1997+1996

phải nói tính tổng hay so sánh gì đó chứ

quên nha rút gọn

KQ = 995

máy tính đâu? lôi ra!

\(\dfrac{1995x1997-1}{1996x1995+1994}=\dfrac{1995x\left(1996+1\right)-1}{1996x1995+1994}\)

\(=\dfrac{1995x1996+1995-1}{1996x1995+1994}=\dfrac{1995x1996+1994}{1996x1995+1994}=1\)

1