Question

Tính nhanh:

1993 * 1991 - 1/1992 + 1990 * 1993

Hãy trình bày ra.

Answer 1

\(\frac{1991.1993-1}{1992+1990.1993}=\frac{1990.1993+1993-1}{1992+1990.1993}=\frac{1992+1990.1993}{1992+1990.1993}=1\)

Answer 2

\(\frac{1993.1991-1}{1992+1990.1993}=\frac{1993.\left(1990+1\right)-1}{1992+1990.1993}=\frac{1993.1990+1993-1}{1992+1990.1993}=\frac{1993.1990+1992}{1992+1990.1993}=1\)

Answer 3

\(\frac{1993\times1991-1}{1992+1990\times1993}=\frac{1993\times1990+1993-1}{1992+1990\times1993}=\frac{1993\times1990+1992}{1992+1990\times1993}=1\)