That 's easy!!! (x-h) ²+(x-k) ²=r²
(h, k) is the coordinate of centra
r is radius
and(x-h) ²+(x-k) ²=r² is written in standard form, which u can directly get the value of center and radius
so for ur question center is (7 and -4)
radius is 7
13/15 = 87%
This is because 13 divided by 15 is 87, so 13 is 87% of 15:)
Put the graph dude I can’t tell what your trying to say :)