15 is dividing on the right, then it will multiply on the left
9 is dividing on the left, then it will multiply on the right
[tex]\begin{gathered} 4\cdot15=x\cdot9 \\ 60=x\cdot9 \end{gathered}[/tex]Now, 9 is multiplying on the right, then it will divide on the left
[tex]\frac{60}{9}=x[/tex]