What is the solution set for the open sentence with the given replacement set? 15−x=9, {5, 6, 7, 8}
dont scam for points pls i need this

Given a circle with measures of (c, d, and r) and a circle with measures of (c', d', and r'), what is d if c c' = 12 and d' = 0.50? a) 3 b) 6 c) 12 d) 24