Question

if x-1 and x+2 are factors of 3x3+ax2-bx+b+2c. find value of a+2b-c​

Answer 1

Step-by-step explanation:

(x+3) is one factor which means x = -3. Substitute -3 for x to ... (1). When divided by (x- 2) the polynomial yields a remainder of 15. ... 4a - 2b = -4, or. 2a - b = -2 … (2).

Answer 2

Given:

• x-1 and x+2 are factors of $3x3+ax2-bx+b+2c$

Find:

value of a+2b-2c​

Step-by-step explanation:

• 1 is a factor of equation so when we put $x=1$ equation must be zero$3+a-b+b+2c=0\\a+2c=-3$
• -2 is also a root so $3(-2)^{3} +a(-2)^{2}+2b+b+2c=0\\ -24+4a+3b+2c=0\\4a+3b+2c=24$
• $3a+3b+a+2c=24\\3(a+b)-3=24\\3(a+b)=27\\a+b=9$
• on solving these equation we get $b-2c=12$
• so final answer is $a+b+b-2c=9+12=21$