Question

Find k if x = 4 is a root of the quadratic equation kx² – 10x - 8 = 0


option1. 4
option2. 3
option3. 8
option4. 10​

Answer 1

Answer:

Step-by-step explanation:

given x=4

kx^2 - 10x - 8 = 0

k(4^2) - 10 * 4 - 8 = 0

16k-40-8=0

16k-48=0

16k=48

k=48/16

k=3

Answer 2

Step-by-step explanation:

x=4

f(x)=k×(4)²-10(4)-8

0=16k-40-8

48=16k

3=k