It’s a ! you add both of the numbers to get your missing perimeter.
I’m very sorry if it’s wrong but this is what I believe! stay safe
X=-8
A negative plus a positive, if ghe negative is bigger it stays negative. -8 is bigger than 5 and 8 - 5 is 3 add the negative and you get -3
Step-by-step explanation:
here are the answers
I hope this help, good luck