The center of a great circle is also the center of a?

What are the interpretations of the line 3x - 15y = 60? x-intercept y-interception a: x 20 - y -4 b: x 5 - y 20 c: x -3 - y 15 d: x -4 - y 20

Which number is composite a.9 b.5 c.11 d.2

Three problems for 50 ! 1- -3t=99 2- 1/6k=-11 3- 4 1/2 +q=9 1/2 show work thx s !