Question

39. If one zero of the quadratic polynomial x2 + 3x + k is 2, then the value of k is
(a) 10 (b) - 10 (c) 5
(d) – 5
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Answer 1

Step-by-step explanation:

p(k)=x^2+3x+k =o

p(2)=2^2+3(2)+k=0

4 + 6 + k =0

10+k =0

so, k= -10

Answer 2

Answer:

k = -10

Step-by-step explanation:

${x}^{2} + 3x + k = 0\\ zero \: of \: polynomial \: is \: 2 \\ x = 2 \\ {2}^{2} + 3(2) + k = 0 \\ 4 + 6 + k = 0 \\ 10 + k = 0 \\ k = - 10$