m x 2 + n x 2 + p x 2 biết:
a) m = 2006, n = 2007, p = 2008
2006 x 2 + 2007 x 2 + 2008 x 2
= (2006 + 2007 + 2008) x 2
=6021 x 2 = 12042
b) m + n + p = 2009
ta có:
m x 2 + n x 2 + p x 2
= ( m + n + p) x 2
mà m + n + p = 2009
suy ra :
m x 2 + n x 2 + p x 2
= 2009 x 2 =4018