Question

If one root of the quadratic eqn x^2-11x+k =0 is 9, then find value of k?

Answer 1

Given equation is x²-11x+k= 9
as soln. of this equation is 9 then put x = 9 in this equation

9² -11*9 + k = 0
81 - 99 + k = 0
-18+ k = 0
k = 18


hence value of k is 18.

@_@

Answer 2

Answer:

Step-by-step explanation:

let the other root be y

therefore two roots will be 9 and y

as the roots sum should be equal to - b/a

therefore 9 + y= -(-11)/1

therefore y = 2

and also the product of roots is equal to c/a

therefore (9)(2) = k/1

therefore k = 18