For f(x) = 7x and g(x) = X + 9, find the following functions. a. (fog)(x); b. (gof)(x); c. (fog)(4); d. (gof)(4)

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.