Answer:

Step-by-step explanation:
Given a second order polynomial expressed by the following equation:

This polynomial has roots
such that
, given by the following formulas:



In this problem, the sum S of the solutions of a quadratic equation is:

So

They have the same denominators, so we can keep the denominators and sum the numerators.



10 and (-9)
ex. 10+-9=1
ex. 10(-9)= -90
Answer: (EF) ax+by+c=0
do you know normal vector? vector EF=(7;3) --> normal vector (-3;7)
---> (EF)-3x+7y+c=0. because (EF) passes through E(1;-3) so -3.1+7.(-3)+c=0 ---> c=24
(EF) -3x+7y+24=0