Help me out I’m down bad for math

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.

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.