Salut!
Efectuati:
a)-2- 7- 9+ 1+ 6- 8+ 4+3+4+2+3-9+5
=-7-10+(-2)+7+6+5-14
=-17+5+11-14
=-12+(-3)
=-15
b)+6-8+2-4+9+2+4+2-5-8-1+7+3
=2+(-2)+11+5+(-3)-7+10
=0+16+(-10)+0
=16+(10)
=6
c)+ 8 - 4 - 9 + 7-1-2-4-5 + 7 - 3 + 2 + 6 + 1
=4-16-(-1)-(-1)-12-5+7
=-12-0-7+7
=-12-14
=-26
d)+ 8 + 5 - 4 - 7- 6- 9- 2 + 3 +9 - 1 + 2 + 3 + 4
=13-(-3)-(-3)-7+12-3+7
=16-(-10)+9+7
=26+16
=42
e)- 6 + 2 - 9 + 7 + 2 + 3 + 4 + 8 + 3 - 9 - 4 + 1 - 5
=-4+(-7)+9+7+11-5+(-4)
=-11+15+6+(-4)
=4+2
=6
f)+ 8 + 2 - 3 - 6 + 1 + 3 + 4 + 2 - 8- 5 + 9- 7- 2
=10-(-3)+4+6-3+2-2
=13+10-5-2
=23-3
=20
Sper ca te-am ajutat!