If x2 – x divides p(x) = x4 – x3 + x2 + ax + b then a + b equals
(a) –2
(b) –1
(c) 1
(d) 3
(e) 5
Target Test Prep is 20% off right now!
Use code FLASH20
Available with Beat the GMAT members only code
MORE DETAILS
Don't Forget About These
This topic has expert replies
-
sureshbala
- Master | Next Rank: 500 Posts
- Posts: 319
- Joined: Wed Feb 04, 2009 10:32 am
- Location: Delhi
- Thanked: 84 times
- Followed by:9 members
If x^2 - x divides P(x) = x^4 - x^3 + x^2 + ax + b, then find the value of a+b.
Given x^2 - x divides P(x).
i.e. x(x-1) divides P(x).
i.e. x-1 divides P(x) [P(x) will be divisible by x if b is divisible by x.]
Hence P(1) = 0
i.e. 1 - 1 + 1 + a + b = 0
Hence a + b = -1
Given x^2 - x divides P(x).
i.e. x(x-1) divides P(x).
i.e. x-1 divides P(x) [P(x) will be divisible by x if b is divisible by x.]
Hence P(1) = 0
i.e. 1 - 1 + 1 + a + b = 0
Hence a + b = -1
