Let:
x = Number of pink roses
y = Number of yellow roses
there are 19 members on the team, so:
[tex]x+y\le19[/tex]the pink roses cost $3 and the yellow roses cost $2 you will spend $50, so:
[tex]3x+2y\le50[/tex]so:
[tex]\begin{gathered} y\le19-x \\ y\le\frac{1}{2}(50-3x) \end{gathered}[/tex]