Friday, February 20, 2015

How to simplify using partial fraction. 5/(x^2-5x+6) ?

We have to express the given expression 5/(x^2-5x+6) as
partial
fractions.


5/(x^2-5x+6)


=>
5 / ( x^2 - 3x - 2x + 6)


=> 5/ ( x(x - 3) - 2( x -
3))


=> 5/ (x - 2)(x -
3)


=> A / (x - 2) + B/ (x -
3)


=> [A(x - 3) + B(x - 2)]/ (x - 2)(x
-3)


Ax - 3A + Bx - 2B =
5


=> Ax + Bx - 3A - 2B =
5


Equate the coefficients of x and the numeric
coefficients


=> A + B = 0 and 3A + 2B =
-5


=> A = -B


Substitute
in 3A + 2B = -5


=> -3B + 2B =
-5


=> B = 5


A =
-5


We can write 5/(x^2-5x+6) = 5/(x - 3) -
5/(x - 2).

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