How do you express (x^2+8)/(x^2-5x+6)x2+8x25x+6 in partial fractions?

1 Answer
Apr 21, 2016

(x^2+8)/(x^2-5x+6)=1-12/(x-2)+17/(x-3)x2+8x25x+6=112x2+17x3

Explanation:

(x^2+8)/(x^2-5x+6)x2+8x25x+6

=((x^2-5x+6)+(5x+2))/(x^2-5x+6)=(x25x+6)+(5x+2)x25x+6

=1+(5x+2)/(x^2-5x+6)=1+5x+2x25x+6

=1+(5x+2)/((x-2)(x-3))=1+5x+2(x2)(x3)

=1+A/(x-2)+B/(x-3)=1+Ax2+Bx3

=1+(A(x-3)+B(x-2))/(x^2-5x+6)=1+A(x3)+B(x2)x25x+6

=1+((A+B)x-(3A+2B))/(x^2-5x+6)=1+(A+B)x(3A+2B)x25x+6

Equating coefficients we get:

{ (A+B=5), (3A+2B=-2) :}

Subtract twice the first equation from the second to find:

A = -12

Then substitute this value of A into the first equation to find:

B = 17

So:

(x^2+8)/(x^2-5x+6)=1-12/(x-2)+17/(x-3)