Question

Given that x-3 is a factor of the expression x^3-5x^2+kx-15, show that the value of k is 11.......need help.....

Answer 1

have you heard of the remainder theorem?

Answer 2

well yes......but i couldn't understand the question....

Answer 3

what you do is to substitute 3 (not -3 because you need the 'opposite') into the equation.

\[(3)^3-5(3)^2+k(3)-15\]
now since x-3 is a factor this expresssion ^^ will equal 0 (because there is no remainder)

solve to find d

Answer 4

*k not d

Answer 5

ok...so is it....9-45+3k-15...........and then?

Answer 6

@prasheelasingh make that equal to 0 and then solve for k

Answer 7

k=17?

Answer 8

\[\frac{ 2x+6 }{ 5 }-\frac{x+7}{3}<\frac{3x8}{2}\] help needed please.......

Answer 9

\[<\frac{3x-8}{2}\] correction....

Answer 10

@prasheelasingh the first 3 is cubed, not squared