Help! It's my Chinese school homework!

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.

What are the equivalent ratios for 24/2= /3= /5.5=108/ = /15

20 ! brainliest ! add and simplify your answer.