Question

find the values of K from which equation X²+ 5kx + 16=0 has real and equal roots

Answer 1

x²+5kx+16=0
D=0
b²-4ac=0

a=1
b=5k
c=16

(5k)²-4(1)(16)=0
25k²-64=0
25k²=64
k²=64/25
k=√64/25
k=8/5

Answer 2

Answer:

k = +8/5 and k = -8/5.

Step-by-step explanation:

Proper Question:

Find the values of k for which the equation x²+5kx+16=0 has real and equal roots.

Solution:

Since equation x² + 5kx + 16 = 0 has real and equal roots

So,

b² - 4ac = 0

Hence,

b = 5k, a = 1,c = 16

=> (5k)² - 4(1) (16) = 0

=> 25 k² -64 = 0

=> 25k² = 64

=> k² = 64/25

=> k = √64/25

=> k = +8/5

Or k = -8/5