Answer:

Step-by-step explanation:
Given


Required
Possible values of k
The general quadratic equation is:

Subtract
and 


Factorize:

Rewrite as:

Compare the above equation to: 



For the equation to have two distinct solution, the following must be true:

So, we have:

Expand

Rewrite as:


Expand

Factorize

Factor out k + 6

Split:
or 
So:
or k 
To make the above inequality true, we set:
or 
So, the set of values of k is:

Answer:
Square both sides of the equation given in order to remove the square root.
This falls under geometry. The two labeled angles are congruent, which means the line segment between them (AD in the image) is a bisector of the angle at vertex A. Use the angle bisector theorem, which says that




There are 1000 millimetres in a litre, so 1800 ml is 1.8 litres. 3-1.8 is 1.2.