Question

If one of the zeroes of the quadratic polynomial : (k – 1) x² + kx + 1 is –3, then the value of k is

Answer 1

kx2-x2+kx+1=0

-3=-2k-4×0×1

-3=-2k

k=3/2

Answer 2

$f(x) = (k - 1)x² + kx + 1$

$f(3) = 0$

$(k - 1) × (3)² + (-3)k + 1 = 0$

$(k - 1)9 - 3k + 1 = 0$

$9k - 9 - 3k + 1 = 0$

$6k - 8 = 0$

$6k = 8$

$k = \frac{8}{6}$

$k = \frac{4}{3}$