Meera sets up the long division shown but does not want to finish it. Using the remainder theorem, what is the remainder?
Class 9PolynomialsPolynomials
A2
B−64
C5
D74
Step-by-Step Solution
Dividing by x−3 leaves remainder p(3)=27−36+6+5=2. Using p(−3) gives −64, a sign slip.
Answer: A) 2
Key idea: Remainder Theorem
**When p(x) is divided by (x−a), the remainder = p(a).**
Don't do long division — just substitute x=a into the polynomial.
Example: divide p(x)=x3−2x+1 by (x−2). Remainder = p(2)=8−4+1=5.
Why it works: any polynomial can be written as p(x)=q(x)×(x−a)+r, where r is a constant remainder. Substituting x=a kills the q(x)×(x−a) term, leaving p(a)=r.
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