Question

find the value of k, for which one root of the quadratic equation kx2- 14 x + 8 = 0 is 2 . ( 2 in kx2 is square)

Answer 1

Answer:

Since 2 is one root of the quadratic equation,

We substitute X=2

k(2)^2 - 14(2) +8= 0

4k-28+8=0

4k-20=0

4k=20

k=5

Hope you found useful

Answer 2

since they have given the quadratic equation is

$k {x }^{2} - 4x + 8 = 0$

they have also given that it has only one root is 2

we will substitute x=2

$k {(2)}^{2} - 4(2) + 8 = 0 \\ \: \: \: \: \: \: \: \: \ 4k - 28 + 8 = 0 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 4k - 20 = 0 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 4k = 20 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: k = \frac{28}{4 } \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: k = 5$

so the value of k=5