Question

[Khánh Linh]

Tính hợp lí:

1) 5 - ( 1997 - 2005 ) + 1997

2) 4567 + ( 1234 - 4567 ) - 4

Answer 1

[Hoang Hung Quan]

\(1)5-(1997-2005)+1997\)

\(=5-1997+2005+1997\)

\(=(-1997+1997)+(5+2005)\)

\(=0+2010\)

\(=2010\)

\(2)4567+(1234-4567)-4\)

\(=4567+1234-4567-4\)

\(=(4567-4567)+(1234-4)\)

\(=0+1230\)

\(=1230\)