Coefficients are the numbers in a equation variables are the letter
Answer:
See Explanation;
Step-by-step explanation:
The given vectors are;
and 
a) To add or subtract two vectors, we add or subtract their corresponding components









b) See attachment for graphs(1,6
Answer:

Step-by-step explanation:
Simply use the fact that the change in x squared + the change in y squared = the distance squared. (The Pythagorean Theorem)
1^2 + 4^2 = d^2
1 + 16 = d^2
17 = d^2
d = √17
Hope it helps :)
<h2>1)</h2>

This must be true for some value of x, since we have a quantity squared yielding a positive number, and since the equation is of second degree,there must exist 2 real roots.

<h2>2)</h2>
Well he started off correct to the point of completing the square.

-1(5x+1)
-5x-1
the (-) in front is just a short way to put (-1)