So first we need to represent our problem with the restriction we have.
[tex]0.75x+0.50y=6[/tex]and the other restriction is:
[tex]x+y=9[/tex]from the second equation we can solve for x, and it will be:
[tex]x=9-y[/tex]and replace that into the first equation:
[tex]0.75(9-y)+0.50y=6[/tex]and now we solve for y
[tex]\begin{gathered} 7.11-0.75y+0.50y=6 \\ 7.11-6=0.75y-0.50y \\ 1.11=0.25y \\ y=\frac{1.11}{0.25} \\ y=4.44 \end{gathered}[/tex]with this solution we can solve the second equation:
[tex]\begin{gathered} x+4.44=9 \\ x=9-4.44 \\ x=4.56 \end{gathered}[/tex]This is one of the posible solution, now you can play with the decimals, so for example 4 peaches and 6 apples, or 6 peaches and 4 apples