Find the value of a and b, if 2 and 3 are zeros of x3+ax2+bx-30
Answers
Answered by
29
Answer: -10 and 31 respectively-
Step-by-step explanation:
Given that, 2 and 3 are the zeroes of x^3+ax^2+bx-30
p(x)=x^3+ax^2+bx-30
Now,
p(2)=(2)^3+a(2)^2+b(2)-30
=8+4a+2b-30
=4a+2b-22
=2a+b-11
2a+b=11 ...(1)
And
p(3)=(3)^3+a(3)^2+b(3)-30
=27+9a+3b-30
=9a+3b-3
=3a+b-1
3a+b=1 ...(2)
Since 2 and 3 are zeroes of given polynomial.
So, subtracting (1) and (2)
2a+b=11
3a+b=1
_________
-a=10
a=-10
Substituting a=-10 in (1),
2(-10)+b=11
-20+b=11
b=11+20
b=31
Therefore,the value of a and b are –10 and 31 respectively.
Answered by
9
Step-by-step explanation:
2a+b=11
3a+b=1
=-a=10
a=-10
2(-10)+b=11
-20+b=11
b=11+20
b=30
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