100 points! Please answer quickly, I'm lost and I need help with both of these worksheets! Please show how you got the answers

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 is the slope of the line shown below?

Twelve less than a number is at most 20