Explicație pas cu pas:
a)
[tex]2009 \times (2009 + 2008 - 4018) = 2009 \times (4017 - 4018) = 2009 \times ( - 1) = - 2009[/tex]
b)
[tex]1957 \times (1959 - 1958) = 1957 \times 1 = 1957[/tex]
c)
[tex]2009 \times (2010 + 2008 - 4017) = 2009 \times (4018 - 4017) = 2009[/tex]
d)
[tex]2009 \times (2009 + 2008 - 4017) = 2009 \times (4017 - 4017) = 2009 \times 0 = 0[/tex]
