Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Quadratic equations - does anyone have an easy method?
Does anyone have an easy method for solving a quadratic equation where x^2 has a co-efficient higher than 1? For example 5x^2 + 9x - 2 = 0
2 Answers
- 1 decade agoFavorite Answer
Plug it into the quadratic formula.
Basically, get it into "ax^2 + bx + c = 0" form first, as you've already done in your equation.
Then plug it into the quadratic formula:
x = (-b +/- sqrt(b^2 - 4ac))/2a
You'll have two answers (one for + -b, one for - -b), which will be your solution set. For ex, if you got 7 and 2, then you would say x={7,2}. However, before you do anything, plug your numbers into this section of the equation first: sqrt(b^2 - 4ac). If that number is the sqrt of a negative number, then the formula cannot be applied.
- 1 decade ago
I don't know that I have an "easy" method... but here are a couple of links that might help. The first is a lesson on solving quadratic formulas that is VERY good and very clear.
The second is a tool for solving them that explains the work in solving that particular problem. I used it for yours and came up with:
http://www.webmath.com/cgi-bin/quadform.cgi?a=5&b=...
Hope this helps :)
Source(s): PurpleMath http://www.purplemath.com/modules/index.htm WebMath (calculators of different kinds, they explain the steps as well) http://webmath.com/
