The chart shows how many people have signed up to go on a field trip each day

When keisha installed a fence along the 200 foot perimeter of her rectangular back yard, she left an opening for a gate.in the diagram below, she used x to represent the length in feet of the gate? what is the value? a. 10 b. 20 c. 25 d. 30

Answer! if you don’t mind, can you explain

Asequence is a function whose is the set of natural numbers