Samantha had to add this group of numbers (47 + 56 + 53), but she wanted to add them as quickly and as easily as possible. here is how she decided to add the numbers: 47 + 56 + 53 = (47 + 53) + 56 = 100 + 56 = 156. which number property allowed her to add the numbers in this way?

99 points at a zoo, the leopard pen has a ring-shaped sidewalk around it. the outer edge of the sidewalk is a circle with a radius of 12 m. the inner edge of the sidewalk is a circle with a radius of 8 m. (1 point for showing all of your work) a. write and simplify an expression for the exact area of the sidewalk. (1 point for the answer) b. find the approximate area of the sidewalk. use 3.14 to approximate π. (1 point for the answer)

Brent needs to paint a logo made using two right triangles. the dimensions of the logo are shown below. what is the difference between the area of the large triangle and the area of the small triangle? (1 point) select one: a. 4.5 cm2 b. 8.5 cm2 c. 16.5 cm2 d. 33.0 cm2

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?