Which is an example of the associative property?
a. –(18 + 3) = –18 + (–3)
b. –17 + 0 = –17
c. (–8 + 10) + 4. = –8 + (10 + 4)
d. –5 + 7 = 7 + (–5)

Which of these choices show a pair of equivalent expressions?

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.

Use the given information to determine the exact trigonometric value.