Is the following relation a function? If not, why? (3, 4), (6, 4), (5, - 4), (2, 1), (3, - 6)

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.

Can someone me do math because i am having a breakdown rn because i don’t get it

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?