We have the following:
We have that the input variable is the cups of flour (f) and the output variable is the brownies.
Therefore, it would be:
[tex]\begin{gathered} b=\frac{6}{2.5}f \\ b=\frac{12}{5}f \\ \end{gathered}[/tex]check:
[tex]b=\frac{12}{5}\cdot2.5=2.4\cdot2.5=6[/tex]