Question

Help me PLease and no incorrect answers only answer if your sure, Show your work for each one please. And take your time.

Answer 1

21) 4

because -13-(-17) when 2 negatives are next to each other they cancel out and turn into positives the just -13+17

And 22 is 33 because the 2 negatives cancel out and turn into positives so 23+9

I am sorry but the rest I can't solve

Explanation: