Tuesday, March 31, 2009

Solving quadratic equation

Problem on how to solve a quadratic equation:

Know more about quadratic equations http://en.wikipedia.org/wiki/Quadratic_equation

Question:
(x + 2) / (x - 3) = 42 (x + 7)

Solution:

(x +2 ) (x + 7) = 42 (x - 3)

x² + 7x + 2x + 14 = 42x - 126

x² + 9x + 14 = 42x - 126

x² + 9x + 14 - 42x + 126 = 0

x² - 33x + 140 = 0

Using Factorization


x² - 28x - 5x + 140 = 0


Taking out common factors

x(x - 28) -5(x - 28) = 0

(x - 5) (x - 28) = 0
x -5 = 0
OR
x - 28 = 0


Either

x = 5

OR

x = 28

For more help on solving quadratic equations.



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