Answer:
Part 1) The maximum number of pounds of regular coffee that you can buy is 7.5 pounds.
![x\leq 7.5\ pounds](https://img.qammunity.org/2020/formulas/mathematics/high-school/gyv81ghe5x2vjapygsxxpcn92xva8m6aoc.png)
Part 2)
![m+n=(0.76x-0.28)](https://img.qammunity.org/2020/formulas/mathematics/high-school/xenlae0fhr2llro3emxg3i0oahhyukfhdy.png)
Explanation:
Part 1)
Let
x-----> the number of pounds of regular coffee
we know that
The inequality that represent the situation is
![2x\leq 15](https://img.qammunity.org/2020/formulas/mathematics/high-school/aquopedf4r0e1pv2zdnd01ue4v6bbvvr0p.png)
Solve for x
Divide by 2 both sides
![x\leq 15/2](https://img.qammunity.org/2020/formulas/mathematics/high-school/3f96yu0awmrlm484dx990seq4wuas8d8h5.png)
![x\leq 7.5\ pounds](https://img.qammunity.org/2020/formulas/mathematics/high-school/gyv81ghe5x2vjapygsxxpcn92xva8m6aoc.png)
The maximum number of pounds of regular coffee that you can buy is 7.5 pounds.
The solution of the inequality is the interval ------> (-∞,7.5]
but the number of pounds cannot be a negative number
therefore
The solution is the interval -----> [0,7.5]
see the attached figure
Part 2) we have
![m=0.56x-0.25](https://img.qammunity.org/2020/formulas/mathematics/high-school/lov71ascp0ci5mj20t02jjql68h4kf2ma3.png)
![m=0.20x-0.03](https://img.qammunity.org/2020/formulas/mathematics/high-school/xhsxup7psoa9wk7yzas48mw64cc9a7z6fy.png)
Adds m and n
![m+n=(0.56x-0.25)+(0.20x-0.03)](https://img.qammunity.org/2020/formulas/mathematics/high-school/5it06iimvfauniv46efvqg5vffgl2xbz4l.png)
Group terms that contain the same variable
![m+n=(0.56x+0.20x)+(-0.25-0.03)](https://img.qammunity.org/2020/formulas/mathematics/high-school/4lh6os3lkgbbpvdk1rl7btirayygpgnd1g.png)
Combine like terms
![m+n=(0.76x-0.28)](https://img.qammunity.org/2020/formulas/mathematics/high-school/xenlae0fhr2llro3emxg3i0oahhyukfhdy.png)