The extraneous root is
x = 2
It would be =-5f
Hope this helps
(2x - 3y + 5z) - (-4x - y + 8z)
= 2x - 3y + 5z + 4x + y - 8z
= 6x - 2y - 3z
In short, Your Answer would be Option D
Hope this helps!
Let 
be the amount of food needed for one man for one day. At the beginning, we have enough food for 400 men for 40 days, i.e.
After 10 days, the 400 men will have consumed
food, impliying that the food remaining is
If 200 more men join the garrison, there are now 600 men. Each of them requires food each day, and there are 
units of food remaining. They will last
days.
