Question

If one root of x2-kx+5=0 is 2 find other root

Answer 1

x^2+kx+5 =0
as two is the root of this equation. After putting two in place of x the equation will be equal to zero.
2^2 + 2k + 5 = 0
4 + 2k + 5 = 0
9 + 2k = 0
2k = -9
k = -9/2

x^2 - 9/2x + 5 = 0
x^2 - 5/2x - 4/2x + 5 = 0
x ( x - 5/2 ) - 2 ( x - 5/2 ) = 0
(x - 5/2)(x-2)=0

therefore the other root is
x-5/2=0
x = 5/2