JAMB - Mathematics (1983 - No. 9)
If (x + 2) and (x - 1) are factors of the expression \(Lx^{3} + 2kx^{2} + 24\), find the values of L and k.
1 = -6, k = -9
1 = -2, k = 1
k = -1, 1 = -2
1 = 0, k = 1
k = 0,1 = 6
설명
f(x) = Lx3 + 2kx2 + 24
f(-2) = -8L + 8k = -24
4L - 4k = 12
f(1):L + 2k = -24
L - 4k = 3
3k = -27
k = -9
L = -6
f(-2) = -8L + 8k = -24
4L - 4k = 12
f(1):L + 2k = -24
L - 4k = 3
3k = -27
k = -9
L = -6