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If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

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.

Math each whole number with a rational,exponential expression