I need help with this 1 question and also can you explain to me how you do it

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.

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?

How can you tell when x and y are not directly proportional?