Question

Find the valu of k for which(3x 2)is a factor of x³ kx²–7x k

Answer 1

If 3x + 2 is a factor then, by the remainder theorem, f(-2/3) = 0 

(-2/3)³ + k(-2/3)² - 7(-2/3) + k = 0 

-8/27 + 4/9k + 14/3 + k = 0 

12/27k + 27/27k = 8/27 - 126/27 

39k = -118 

k = -118/39