Question

if the equation x^2 (k+ 4) x+ 2 k + 5 = zero has equal roots find the value of k​

Answer 1

Answer:

Step-by-step explanation:

b^2-4ac=0 then the roots are equal

here b=k+4

a=1

c=2k+5

b^2=(k+4)^2=k^2+8k+16

4ac=4*(1)*(2k+5)=8k+20

k^2+8k+16-8k-20=0

k^2=4

k=2

Answer 2

★ Answer :

We know that when roots are real and equal then D is 0.

So,

$\Large{\star{\boxed{\sf{D = b^2 - 4ac}}}}$

→ 0 = (k + 4)² - 4(1)(2k + 5)

→ 0 = k² + 16 + 8k - 8k - 20

→ k² - 4 = 0

→ k² = 4

→ k = √4

→ k = ±2

$\Large{\star{\boxed{\sf{k = \pm 2}}}}$