Help please.! What is the number of ways to arrange 5 objects from a set of 9 different objects?
A. 126
B. 532
C. 19,310
D. 15,120

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Worth 30 points! in this diagram, both polygons are regular. what is the value, in degrees, of the sum of the measures of angles abc and abd?