1 centimetre=0.1 decimetre
therefore the answer is 2.5 decimetres.
I know this isn't an answer but I've totally borrowed your profile pic and I hope you don't mind.. xD
If you divide both sides by -4 you'll get:
-10x -12
The required coordinate of A will be at (-4, 0)
When a point bisects a line, it cuts the line into two equal parts and the point on that line is known as its midpoint. The expression for calculating the midpoint of a line is expressed as;
where:

From the question, we are given the following coordinate points

Get x₂;

Get y₂;

Hence the coordinate of A will be (-4, 0)
Learn more about the midpoint here: brainly.com/question/18315903