Question

If `x= - 5 ` is a root of the quadratic equation `kx^(2) + 13x - 10 = 0 `, then complete the following activity to find the value of k .

Answer 1

Activity `:`
One root of the quadratic equation `kx^(2) + 3x - 10 = 0 ` is -5.
Substitute `x= - 5 ` in the equation .
`:. K ( - 5)^(2) + 13( - 5) - 10 = 0 `
`:. 25k - 65 - 10 = 0 `
`:. 25 k = 75 `
`:. K = ( 75)/( 25) = 3 `
The value of k is 3.