Find the value of k such that: 5x-2 is a factor of x^3-3x^2+kx+15.

2 answers

let f(x) = x^3-3x^2+kx+15
if 5x-2 is a factor, then f(2/5) = 0

f(2/5) = 8/125 - 12/25 + (2/5)k + 15 = 0
(2/5)k = - 1823/125
k = - 1823/50
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