Expert: Paul Klarreich - 4/30/2009

Question
i have to solve this quadratic equation and i get get myself confused on how to do it. 2xsquared+11x+14=0 and also x squared=15-2x. i need to learn how to do for doing exams. thankyou for your help

Answer
Questioner:   Helen
Country:  United Kingdom
Category:  Advanced Math
Private:  No
 
Subject:  factorisation or quadratic formulas
Question:  i have to solve this quadratic equation and i get get myself confused on how to do it. 2x^2+11x+14=0 and also x squared=15-2x. i need to learn how to do for doing exams. thankyou for your help
 
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Hi, Helen,

To send me questions, you must write 'factorization'.  I don't speak UK-ese.

Anyway:

2x^2 + 11x + 14 = (2x + 7)(x + 2)

and  that gives you  x = -7/2,  x = -2.

x^2 = 15 - 2x  should be rewritten:

x^2 + 2x - 15 = 0 and then

(x + 5)(x - 3) = 0, so

x = -5 and x = 3.

There are lots of examples in your textbook, and not enough space here to teach you the whole subject of factoring.  {I have a limit of 10,000 lines of text per message.}

Practice on a few hundred of these (I am not kidding) and you will soon get the hang of it.

First, practice multiplying binomials, then re-factoring them.  It is going to take time.  You won't be ready by tomorrow.