Answer
No solution
Work Step by Step
$15f+9\gt3(5f+3)\longrightarrow$ multiply using the distributive property
$15f+9\gt15f+9\longrightarrow$ subtract 15f from each side
$15f+9-15f\gt15f+9-15f\longrightarrow$ subtract
$9\gt9$
Since this inequality is false, there is no solution.