I need help with a question

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.

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?

What three-dimensional solid have 6 rectangular faces, 2 equal bases that are not rectangles and 18 edges