Question

         1999 x 2011 - 1999

________________________

        2010 x 1998 - 2010

Answer 1

= 1999*(2011-1)/2010*(1998-1)

= 1999*2010/2010*1997

=1999/1997

Answer 2

\(\frac{1999\times2011-1999}{2010\times1998-2010}\)

\(=\frac{1999\times\left(2011-1\right)}{2010\times\left(1998-1\right)}\)

\(=\frac{1999\times2010}{2010\times1997}\)

\(=\frac{1999}{1997}\)

_Chúc bạn học tốt_

Answer 3

=1999x(2011-1) /2010x(1998+1)

=1999x2010/2010x1999

=1

nếu đúng k mình nhé !

Answer 4

1999×2011 - 1999 /2010×1998-2010 =1999×2011-2010×1/2010 ×1998-2010×1 =1999×(2011-1) / 2010×(1998-1) =1999×2010/2010×1997 =4017990/4013970

Answer 5

\(\frac{1999\cdot2011-1999}{2010\cdot1998-2010}\)

=\(\frac{1999\cdot\left(2010+1\right)-1999}{2010\cdot1998-2010}\)

=\(\frac{1999\cdot2010+1999-1999}{2010\cdot1998-2010}\)

= \(\frac{1999\cdot2010+0}{2010\cdot1998-2010}\)

= \(\frac{\left(1998+1\right)\cdot2010+0}{2010\cdot1998-2010}\)

= \(\frac{1998\cdot2010+2010+0}{2010\cdot1998-2010}\)

= \(\frac{1998\cdot2010+2010}{2010\cdot1998-2010}\)

= 1