The first term in an arithmetic sequence is 5. The fourth term in the sequence is −4. The tenth term is −22.
Which function can be used to find the nth term of the arithmetic sequence?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of