Working on corresponding parts and finding the values. I don’t understand This???

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle

The width of a rectangle is 20 units. can the perimeter p of the rectangle be 64 units when its length x is 11 units? no, because p = 2x + 2(20) no, because p ≠ 2x + 2(20) yes, because p ≠ 2x + 2(20) yes, because p = 2x + 2(20)

What is the value of x when x + 7 = 21?