Question

find the value of k =?
please sove this question ​

Answer 1

Answer:

k = - 22

Step-by-step explanation:

given : x -2 = 0

x = 2

put the value of x in this equation

3 (2)^2 + 5 (2) + k = 0

3(4) + 10+k = 0

12+ 10 + k = 0

22 + k = 0

k = -22

Answer 2

☃️ Question :-

If -2 is the zero of the quadratic equation $\sf 3x^2+5x+K=0$, then find the value of K.

☃️ Solution :-

It is given that -2 is the zero of $\sf 3x^2+5x+K=0$.

Substituting x = -2 in the equation :-

$\red \mapsto \sf 3(-2)^2+5(-2)+K=0$

$\red \mapsto \sf 3(4)-10+K=0$

$\red \mapsto \sf 12-10+K=0$

$\red \mapsto \sf 2+K=0$

$\red \mapsto \sf K=-2$

⭐Therefore, K = -2 for the given equation when -2 is the root.

☃️ Verification :-

Substituting x = -2 and K = -2 in the given equation for verifying :-

$\red \mapsto \sf 3(-2)^2+5(-2)+(-2)=0$

$\red \mapsto \sf 3(4)-10-2=0$

$\red \mapsto \sf 12-10-2=0$

$\red \mapsto \sf 2-2=0$

$\red \mapsto \sf 0=0$

⭐Hence, verified !!