How to state domains of the function y=

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.

Ineed to know the ordered pairs for this equation i need the answer quick because it’s a timed test

Which equation can be used to determine the reference angle, r, if 0=7 pi/12?