Question

2. If one zero of the quadratic
polynomial x^2+3x+k is 2, then
the value of k is *
O:
8
O O O
O 10
-10
O 8​

Answer 1

Step-by-step explanation:

(2)²+3(2)+k=0

4+6+k=0

k=-10 OK friend this is urs

Answer 2

$\large\bf\underline{Correct\: Question:-}$

If one zero of the quadratic polynomial x²+3x+k is 2 , then find the value of k.

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$\large\bf\underline{Given:-}$

• p(x) = x² + 3x + k
• One zero = 2

$\large\bf\underline {To \: find:-}$

• Value of K .

$\huge\bf\underline{Solution:-}$

»» One zero = 2

So, (x -2) is a factor of given polynomial. Then x = 2.

Putting value of x = 2 in the given polynomial:-

• p(x) = x² + 3x + k

➝ 2² + 3×2 + k =0

➝ 4 + 6 + k = 0

➝ 10 + k = 0

➝ k = -10

So,

• ≫ Value of k is -10

$\large\underline{\bf\bigstar \: Verification:-}$

• p(x) = x² + 3x - 10

➝ x² + 3x - 10

➝ x² - 2x + 5x - 10

➝ x(x - 2) + 5(x - 2)

➝ (x + 5) (x - 2)

➝ x = -5 or x = 2

• ≫ x = -5 or x = 2

So, we get the same zero that is given in the Question.

So value of » k = -10 is correct.