Solve this math problem
Answers
Answer:
a = 0.2 , b = -7.4
Step-by-step explanation:
Given :
(x - 2) is a factor of the equation x³ + ax² + bx + 6 &
(x + 3) gives reminder 3 when the equation was divided by it,.
To Find :
The values of a & b,
Solution :
By dividing the equation by (x - 2) (1st picture) & (x + 3) (2nd picture)
We obtain 2 equations,
As the 1st & 2nd part of the answer is given in pictures below,
the 3rd part is here,.
⇒ 2a + b + 7 = 0 ...(i)
⇒ b - 3a + 8 = 0 ...(ii)
By subtracting (ii) from (i),
⇒ ( 2a + b + 7) - (b - 3a + 8) = 0 + 0
⇒ 2a + 3a + b - b + 7 - 8 = 0
⇒ 5a - 1 = 0 ⇒ a = = 0.2
By substituting value of a in (ii),
We get,
⇒ b - 3(0.2) + 8 = 0
⇒ b - 0.6 + 8 = 0
⇒ b + 7.4 = 0 ⇒ b = - 7.4
Answer:
p(x)=x^3(x raise to power 3) +ax^2 + bx+6
Since x-2 is a factor of this polynomial,2 is a zero of this polynomial.
When we put the value of 2 in x:
(2)^3 +a(2)^2+b(2)+6
=8+4a+2b+6
=14+4a +2b
4a+2b=-14(equation 1)
It is given that when this polynomial is divided by x+3 it gives a remainder 3.
By long division(photo attached ) the remainder comes out to be -12-3b.
Since remainder is equal to 3
-12-3b =3
-3b=3+12
-3b=15
b=-5.
Put this value of b in equation 1
4a+2(-5)=-14
4a=-14+10
4a=-4
a=-1.
Therefore,a=-1 and b=-5.