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Question : 107 of 160
Marks:
+1,
-0
Solution:
| x2+x+1 |
| (x−1)(x−2)(x−3) |
= ++ ⇒x2+x+1=A(x−2)(x−3) +B(x−1)(x−3)+C(x−1)(x−2) Put
x=1,2 and 3 respectively we get
1+1+1=A(1−2)(1−3) ⇒
3=2A⇒A= 22+2+1=B(2−1)(2−3) ⇒7=−B⇒B=−7 and
32+3+1=C(3−1)(3−2) ⇒
13=2C⇒C= ∴
A+C=+=8
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