A Quadratic Equation can have upto 2 roots maximum. So,if one of the roots is a Real number, there are following two possibilities:
1) The other root is also a real number, but a different number
2) Its a repeated root, so the other root is the same number.
The other root cannot be a complex number as its not possible for one root to be real and other to be complex. Either no root will be complex or both will be complex roots.
Following are 3 possibilities for the roots of a quadratic equation:
there was 20 dogs in total he took 1 black dog now 19 in total, now 9 black dogs and 10 brown dogs so one less probability of black dogs so 9 black dogs and 10 brown dogs so 9/19
There are 10 feet of posts on each side. That means there are 40 feet of fencing in total. If you divide that by two (to represent posts being 2 feet apart) then you get 20. There are 20 posts needed.