Which property of equality was used to solve this equation?

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

For what values of x is x2 + 2x = 24 true?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount