amp;I=∫5(x−1)4(x+3)61dxamp;x−1x+3=t⇒dx=(t−1)2−4dt⇒x=(t−13+t)amp;⇒(x−1)4(x+3)6=(x−1)5(x+3)5(x−1x+3)amp;I=∫t1/5(t−13+t−1)(t−33+t+3)(t−1)2−4dtamp;I=∫t1/5(16t)−4dt=45(x+3x−1)1/5+c
Comparing,
amp;⇒A=45,B=51,α=1,β=1amp;⇒α+β+20AB=1+1+20×45×51=7