One of the roots of the equation kx^2 - 2x - 3 = 0 is -3. Find the value of k.
+33615 We must have: (x + 3)(kx - a) = 0
So: kx2 + (3k-a)x - 3a = 0.
Compare term by term with kx2 -2x - 3 = 0
Clearly a = 1, so 3k - 1 = -2
3k = -1
k = -1/3
.
+36916 Another method: SUbstitute in -3 fo 'x' and solve for 'k'
k(9) + 6-3 = 0
k(9) = -3
k = -3/9 = -1/3
