SOLUTION: Show that the sum of the roots of a quadratic equation is -b/a. I know this involves the quadratic formula but not sure of the set up. Do I add or multiply two quadratic form

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Show that the sum of the roots of a quadratic equation is -b/a. I know this involves the quadratic formula but not sure of the set up. Do I add or multiply two quadratic form      Log On


   

Question 1207449: Show that the sum of the roots of a quadratic equation is -b/a.

I know this involves the quadratic formula but not sure of the set up.
Do I add or multiply two quadratic formulas to get -b/a?
Found 2 solutions by ikleyn, Theo:
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.

The word "sum" means "add"         (in case if you do not understand the meaning of the word "sum").

Write the quadratic formulas for the two roots and add them to get the formula for the sum of the roots.



Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
see my worksheet.