How can you find the surface area of a cube with a edge length 3 in?

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

3x = 729 solve for x plz . it's urgent. will mark

Adele is five years older than timothy. in three years, timothy will be 2/3 of adele’s age. what is adele‘s current age?