20)If sum of remainders obtained by dividing ax^3-3ax^2+7x+5 by(x-1)and(x+1)is-36 the find a
Answers
Answered by
6
Answer:
We have, p(x) = ax3 − 3ax2 + 7x + 5Let q(x) = x + 1
; r(x) = x + 2By remainder theorem, when p(x) is divided by q(x), then remainder is given by p(−1).
Now, p(x) = ax3 − 3ax2 + 7x + 5
⇒p(−1) = a(−1)3−3a(−1)2+7(−1)+5
⇒p(−1) = −a − 3a − 7 + 5⇒p(−1) =−4a − 2
By remainder theorem, when p(x) is divided by r(x), then remainder is given by p(−2).
Now, p(x) = ax3 − 3ax2 + 7x + 5
⇒p(−2) = a(−2)3−3a(−2)2+7(−2)+5
⇒p(−2) =−8a − 12a − 14 + 5
⇒p(−2) =−20a − 9
Now, p(−1) + p(−2) = −36
⇒ (−4a − 2) + (−20a − 9) = −36
⇒−4a−2−20a−9=−36
⇒−24a−11 = −36⇒24a + 11 = 36⇒24a = 36 − 11
⇒24a = 25
⇒a = 25/24
Answered by
3
the answer is 23/3
please mark me as Brainlist
Attachments:
Similar questions