Monoxdifly
MHB
- 288
- 0
The remainder of $$p(x)=x^3+ax^2+4bx-1$$ divided by $$x^2+1$$ is –5a + 4b. If the remainder of p(x) divided by x + 1 is –a – 2, the value of 8ab is ...
A. $$-\frac34$$
B. $$-\frac12$$
C. 0
D. 1
E. 3
Dividing p(x) by $$x^2+1$$ by $$x^2+1$$ with –5a + 4b as the remainder using long division, I got (4bx – 1) – ((a – 1)x + a – 1) = –5a + 4b, thus (4b – a + 1)x + a = –5a + 4b. Does this mean that 4b – a + 1 = 0 since the right hand doesn't have an x term? Or do I need to look for the value of x first? I'm at a loss here.
A. $$-\frac34$$
B. $$-\frac12$$
C. 0
D. 1
E. 3
Dividing p(x) by $$x^2+1$$ by $$x^2+1$$ with –5a + 4b as the remainder using long division, I got (4bx – 1) – ((a – 1)x + a – 1) = –5a + 4b, thus (4b – a + 1)x + a = –5a + 4b. Does this mean that 4b – a + 1 = 0 since the right hand doesn't have an x term? Or do I need to look for the value of x first? I'm at a loss here.