Answer:
A. Matthew meets both of his goals.
Explanation:
Let laptops be represented by L
Let smartphones be represented by S
Matthew wants to sell at least 12 devices and earn at least $4500.
The equation first becomes:
![L+S\geq 12](https://img.qammunity.org/2019/formulas/mathematics/high-school/4rtk8304gn7jamhcc3ibar7qwoll51g9i1.png)
He wants to earn $4500 by selling both products.
![425L+125S \geq 4500](https://img.qammunity.org/2019/formulas/mathematics/high-school/bepzxi57jtkeghak3znrw9i7tcu434exwa.png)
Now we have been given, that Matthew sells 9 laptops and 6 smartphones.
Lets check this:
Putting L = 9 and S = 6;
![9+6\geq 12](https://img.qammunity.org/2019/formulas/mathematics/high-school/54df8mq38i453td3h384misd9ajefk9jk5.png)
=>
(condition fulfilled)
![425(9)+125(6) \geq 4500](https://img.qammunity.org/2019/formulas/mathematics/high-school/7m9myj3gd9stiavaq1x6kbs1xk05bbssd0.png)
=>
![3825+750\geq 4500](https://img.qammunity.org/2019/formulas/mathematics/high-school/pm6nyv8uuwp5giwplv0i745amqt2trgzfx.png)
=>
(condition fulfilled)
Therefore, option A is correct- Matthew meets both of his goals.