Plz help, i don't understand this - plenty of points are granted

Which equation represents a circle with a center at (–3, –5) and a radius of 6 units? (x – 3)2 + (y – 5)2 = 6 (x – 3)2 + (y – 5)2 = 36 (x + 3)2 + (y + 5)2 = 6 (x + 3)2 + (y + 5)2 = 36

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

Which one ? is the answer and how to find this answer