We have the following:
1.
let x a tulips
let y daffodils
therefore:
![\begin{gathered} x+y=15\rightarrow x=15-y \\ 10x+7y=(x+y)8\rightarrow10x+7y=120 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/m4xbqgn15niibnuxjbh0qf8efswn8830rx.png)
solving:
![\begin{gathered} 10\cdot(15-y)+7y=120 \\ 150-10y+7y=120 \\ 10y-7y=150-120 \\ 3y=30 \\ y=(30)/(3)=10 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/b1jyvp34zh7ps9hef78h2p7pn57cdql9v7.png)
for x:
![x=15-10=5](https://img.qammunity.org/2023/formulas/mathematics/college/hulerjxjawadsj2btsa5f5eomknqgv51zq.png)
Therefore, the answer is 5 tulips and 10 daffodils
2.
let x a 30% silver
let y a 55% silver
![\begin{gathered} x+y=800\rightarrow x=800-y \\ 30x+55y=40\cdot(x+y)\rightarrow30x+55y=32000 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5pi7rqaejhjql1fh1qu960ebkmkglgvsso.png)
solving:
![\begin{gathered} 30\cdot(800-y)+55y=32000 \\ 24000-30y+55y=32000 \\ 25y=32000-24000 \\ y=(8000)/(25) \\ y=320 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/sjlcvh8mirh0f053ahixg70psh44irmqii.png)
for x:
![x=800-320=480](https://img.qammunity.org/2023/formulas/mathematics/college/3upgbv80brpeg21ns2rr79t9h8szownaou.png)
Therefore, the answer is 480 pounds of 30% silver and 320 pounds of 55% silver