\(\frac{1993.1991-1}{1992+1990.1993}\)
\(=\frac{1993.1990+1993-1}{1993.1990+1992}=\frac{1993.1990+1992}{1993.1990+1992}=1\)
nha ><
Trả lời
1993.1991-1/1992+1990.1993
=1993.1990+1993-1/1993.1990+1992
=1993.1990+1992/1993.1990+1992
=1.
#)Giải :
\(\frac{1993\times1991-1}{1992+1990\times1993}\)
\(=\frac{1993\times\left(1990+1\right)-1}{1992+1990\times1993}\)
\(=\frac{1993\times1990+1993\times1-1}{1992+1990\times1993}\)
\(=\frac{1992}{1992}=1\)
\(\frac{1993\times1991-1}{1992+1990\times1993}\)
\(=\frac{1993\times\left(1990+1\right)-1}{1992+1990\times1993}\)
\(=\frac{1993\times1990+1993-1}{1992+1990\times1993}\)
\(=\frac{1993\times1990+1992}{1992+1990\times1993}\)
\(=1\)