Đáp án:
`P = -7/15`
Giải thích các bước giải:
`P = (1/2003 + 1/2004 - 1/2005)/(5/2003 + 5/2004 - 5/2005) - (2/2002 + 2/2003 - 2/2004)/(3/2002 + 3/2003 - 3/2004)`
`P = (1/2003 + 1/2004-1/2005)/(5 (1/2003 + 1/2004 - 1/2005)) - (2 (1/2002 + 1/2003 - 1/2004))/(3 (1/2002 + 1/2003 - 1/2004))`
` P = 1/5 - 2/3`
`P = 3/15 - 10/15`
`P = (-7)/15`