a) 1-1+1:1-1+1×1-1+1:1 =
= (1-1) + (1:1) - 1 + (1×1) - 1 + (1:1) =
= 0 + 1 - 1 + 1 - 1 + 1
= 0 + 0 + 0 + 1
= 1
b) 1+1+1+1+1+1-1-1-1×1×1×1+1+1+1:1+1+1+1+1+2+5 =
= (1+1+1+1+1+1) - 1 - 1 - (1×1×1×1) + (1+1) + (1:1)+ (1+1+1+1+2+5)
= 6 - 2 - 1 + 2 + 1 + 4 + 2 + 5
= 4 + 1 + 5 + 7
= 17