Patrick B. answered 06/25/20
Math and computer tutor/teacher
1) x-20 a b
------------- = -------- + -------------
x^2-x-20 (x-5) x+4
2) are you sure the denominator isn't meant to be x^2+20x+20 ?????
Either way, long division is required... I will use the problem as posted which is x^2/(x^2+40)
1
_____________
As written, x^2 + 40 | x^2
x^2 + 40
---------------------
-40
applies linearity property to (1- 40/(x^2+40))
integral [1] - 40 integral[ 1/(x^2+40) ]
1 integrates to x
the p.f.d of the second integral is (ax+b)/(x^2+40)
the unfactorable, irreducable quadratic takes a linear function in the numerator