Peggy had four times as many quarters as nickels. she had $2.10 in all. how many nickels and how many quarters did she have?

if the variable n represents the number of nickels, then which of the following expressions represents the number of quarters?

the possible answers are:
n/4
n
4n
n + 4

In what organelle does photosynthesis take place?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Ithink i know it but i want to be sure so can you me out ?