So, let's say the soft drink equals y and the sandwich equals x.
x + y = 9.9
The sandwich costs 3.5 times as much as the soft drink
x = 3.5y
Therefore, we can replace x with 3.5y since they're the same thing
3.5y + y = 9.9 <-- That's the equation :)
Presumably we're being asked for the line which passes through (3,5) and (-1,5) which is simply
Since 0 isn't above 5 it will stay the same, So 2096 to the nearest thousand will be 2000