Answer:
<h2>90°</h2>
Step-by-step explanation:
First you must calculate the module or the magnitude of both vectors
The module of u is:

The module of v is:

Now we calculate the scalar product between both vectors

Finally we know that the scalar product of two vectors is equal to:

Where
is the angle between the vectors u and v. Now we solve the equation for 

the answer is 90°
Whenever the scalar product of two vectors is equals to zero it means that the angle between them is 90 °
The equation of the line is
.
Solution:
The points on the line are (–6, –3) and (4, –5).

Slope of the line:





Point-slope formula:




Subtract 3 from both sides of the equation.

The equation of the line is
.
I think x = 4, but im not 100% sure so im sorry if it is wrong