Let the cost of rose bushes is x.
Let the cost of a bunch of ornamental grass is y.
It is given that,
Castel spent $69 on 5 rose bushes and 8 bunches of ornamental grass.
That is,
5x+8y=69.
Sumalee spent $42 on 2 rose bushes and 8 bunches of ornamental grass.
That is,
2x+8y=42.
To find x and y:
Subtracting these two equations we get,
[tex]\begin{gathered} 5x+8y=69 \\ -2x-8y=-42 \\ _{---------------} \\ 3x=27 \\ x=9 \end{gathered}[/tex]
Substitute x=9 in second equation we get,
[tex]\begin{gathered} 2(9)+8y=42 \\ 18+8y=42 \\ 8y=24 \\ y=3 \end{gathered}[/tex]
Hence, the cost of rose bushes is $9 and the cost of a bunch of ornamental grass is $3.
