Mark is buying supplies for his students. He is buying a notebook (n) and a pack of pencils for each of his 25 students. Each pack of pencils costs $1.25.

If Mark's total cost is $156.25, which of the following equations can be used to find how much each notebook cost? Select TWO that apply.
A - 25(n) +31.25 =165.25
B - 1.25(n)+25=156.25
C- 25(n)=156.25+31.25
D - 25(n)=156.25−31.25