Question

*If one root of the quadratic equation 2x² + kx – 6 = 0 is 2, the value of k is ………………..*

1️⃣ 1
2️⃣ -1
3️⃣ 2
4️⃣ -2​

Answer 1

Answer:

-1

Step-by-step explanation:

put x=2

then

8+2k =6

k=6-8/2

k=-2/2

=-1

Answer 2

Answer:

Explanation:

Given :

• Quadratic equation, 2x² + kx - 6 = 0.
• One root of the quadratic equation is 2.

To Find :

• The value of k.

Solution :

Given that, one root of the quadratic equation is 2.

.°. x = 2

Given that, quadratic equation, 2x² + kx - 6 = 0.

[ Putting x = 2 ]

=> 2(2)² + k(2) - 6 = 0

=> 2 × 4 + 2k = 6

=> 8 + 2k = 6

=> 2k = 6 - 8

=> 2k = -2

=> k = -2/2

=> k = -1

Hence :

The value of k is -1.