Pls help question in description will mark BRAINLIEST if correct and with proof

Rename mixed numbers before you can subtract are what

Which choice represents the sample space ,s for this event

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