The solution must depend upon k.
It is [-6 +/-sqrt(36 + 4k^2)]/2k
There might be a value of k that would make one root equal to -3, but I don't see it.
The product of two roots would have to be 1/(4k^2) * [36 - (36 + k^2)]
= -1/4
I do not agree with your answer.
One solution of kx^2 +6x-k=0 is -3. Find the other solution
I have the answer as -1/3 is this right?
2 answers
How about doing this :
since x=-3
9k -18 -k = 0
k = 9/4
so your equation is (9/4)x^2 + 6x - 9/4 = 0
or 9x^2 + 24x - 9 = 0
3x^2 + 8x - 3 = 0
since one root is -3, you know one of the factors to be (x+3), the other can be easily reasoned out
(x+3)(3x-1) = 0
so x = -3, the given one or
x = 1/3
You were close.
since x=-3
9k -18 -k = 0
k = 9/4
so your equation is (9/4)x^2 + 6x - 9/4 = 0
or 9x^2 + 24x - 9 = 0
3x^2 + 8x - 3 = 0
since one root is -3, you know one of the factors to be (x+3), the other can be easily reasoned out
(x+3)(3x-1) = 0
so x = -3, the given one or
x = 1/3
You were close.
9 answers