Stupid moment here…

Got to put
(-11x+80)/((x^2)-16x+64)
into partial fractions.

Got
A/(x-8) + B/(x-8)
but no idea how to work out A and B?

Any ideas for a muppet?

Ta, Duane.

I think the fact that you have a "repeated term" [ie. (x-8)^2] in the denominator changes how you do it but I can't for the life of me work out how it goes.

ie. I don't think it's simply

A/(x-8) + B/(x-8)

but

A/[(x-8)^2] + B/(x-8)

but can't remember if it's A or Ax + C on top of your first partial fraction.

Hopefully *some* help? 😯

42

Doing an engineering degree, think this is how u do it.

Its like munkster said

A/(x-8)^2 + B/(x-8)

Then you just work out A and B in the normal way

Cheers

Ah yes, thought I was right but I couldn't get it to work but have just done it…

So

A/(x-8)^2 + B/(x-8)

Multiply second fraction by (x-8) top and bottom

A/(x-8)^2 + B(x-8)/(x-8)^2

Write as one fraction and expand/collect numerator

(A – 8B + Bx)/(x-8)^2

Equate numerator to numerator of original and compare coefficients/constants

So B = -11 and A – 8B = 80

but B = -11 so A + 88 = 80 and A = -8

Works innit… 😉

Thanks a ton mate, worked it out after your first post, cheers 🙂