stuck on math question (1 Viewer)

[Kaatie]

find all the possible values of k if one of the roots of x^2 - kx - (k + 1) = 0 is 6 more than the other


also find all possible roots

 

[shaon0]

find all the possible values of k if one of the roots of x^2 - kx - (k + 1) = 0 is 6 more than the other


also find all possible roots

Let roots be; a and a+6
Sum of roots:
a+a+6 = k
2a+6=k....1
Product of roots:
a(a+6)= -(k+1)
a^2 + 6a +k+1=0 .....2
Sub 1 into 2.

2a+6+a^2+6a+1=0
a^2+8a+7=0
(a+7)(a+1)=0
Thus, a= -7 and -1.....3
Sub 3 into 1.
2a+6=k
k=-8 or 4.

 

[Kaatie]

thanks alot

 

[shaon0]

thanks alot

No worries.