Question

if one root of the given quadratic equation X square + 3 X + k is equal to zero is 5 then the value of k is​

Answer 1

Step-by-step explanation:

hope it helps you!!..

I have made an attempt!33

Answer 2

Given:-

• Equation is $x^{2} + 3x + k$ $= 0$.

• One root of the given equation is 5.

To Find:-

• The value of k.

Solution:-

Here, One root of the equation is 5.

So, $x^{2} + 3x + k$ $= 0$

⇒ $5^{2} + 3 \times 5 + k = 0$

⇒ $25 + 15 + k = 0$

⇒ $k = -40$

Hence, the value of k is -40

Since, we got the value of k let's find another root,

⇒  $x^{2} + 3x - 40 = 0$

⇒  $x^{2} +8x - 5x - 40 = 0$               [ By Middle term splitting ]

⇒  $x(x + 8) - 5(x + 8)$ $= 0$

⇒ $(x + 8) (x - 5)$ $= 0$

⇒ $x = -8 \ and \ x = 5$

Hence, Another root will be -8