Solution:
Given:
Let the cost of each daylily be d
Let the cost of each shrub be s
Generating the system of equations;
[tex]\begin{gathered} 12d+10s=74.................(1) \\ 7d+5s=39.....................(2) \end{gathered}[/tex]Equation (2) multiplied by 2;
[tex]\begin{gathered} 12d+10s=74..............(1) \\ 14d+10s=78...............(2) \\ \\ Subtracting\text{ equation \lparen1\rparen from equation \lparen2\rparen; equation \lparen2\rparen- equation \lparen1\rparen} \\ 14d-12d=78-74 \\ 2d=4 \\ Dividing\text{ both sides by 2;} \\ d=\frac{4}{2} \\ d=2 \end{gathered}[/tex]Substituting the value of d into equation (2);
[tex]\begin{gathered} 7d+5s=39 \\ 7(2)+5s=39 \\ 14+5s=39 \\ 5s=39-14 \\ 5s=25 \\ Dividing\text{ both sides by 5;} \\ s=\frac{25}{5} \\ s=5 \end{gathered}[/tex]Therefore, the cost of one daylily is $2 and the cost of one shrub is $5.