Răspuns:
42:7+(6+6):2-24:(5+3) =
= 42:7+12:2-24:(5+3) =
= 42:7+12:2-24:8 =
= 6+12:2-24:8 =
= 6+6-24:8 =
= 6+6-3 =
= 12-3 =
= 9
(25+20):5-(19+5):8 =
= 45:5-(19+5):8 =
= 45:5-24:8 =
= 9-24:8 =
= 9-3 =
= 6
10+(10:10)-(10×1+10) =
= 10+1-(10×1+10) =
= 10+1-(10+10) =
= 10+1-20 =
= 11-20 =
= -9