Answer:
10x+5
Step-by-step explanation:
You would add 3x and 7x
you would leave 5 alone because it has no x thus it can not be added to the 3x and 7x
It's a Octagon!!!!!!!!!!!!
Step-by-step explanation:
i hope this help if it doesn't ill come back and try to see if i can find another way to do it.