Question

If -3 is a zero of the polynomial x2+ x - (3 + 2k) then find the value of k
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Answer 1

Given :

-3 , is zero of x² + x - (3 + 2k)

To find : k

Property used :

If , "y" is zero of polynomial p(x) = ax² + bx + c. Therefore p(y) will be equal to zero

Steps to follow :

• First of all put x = -3
• Then put p(-3) = 0
• Solve for k

Solution :

Let , x² + x - (3+2k) = p(x)

If x = -3 is zero of polynomial, then p(-3) = 0

p(-3) = (-3)² + (-3) - (3+2k)

0 = 9 - 3 - (3+2k)

0 = 6 - 3 - 2k

2k = 3

k = 3/2

ANSWER :

k = (3/2)