Big sale 20% off what percent of the regular price is taken off ?

Can somebody me out with this question

Suppose the radius of a circle is 16. what issuppose the radius of a circle is 16. what is its circumference its circumference

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.