Question

if the polynomial 9x^3-8x^2+kx+8 leaves a remainder of 998 when divided by x-5 , find the value of k

Answer 1

Answer

p(x)=9x^3-8x^2+kx+8

g(x)=x-5=0

so,x=5

putting in p(x)

9(5)^3-8(5)^2+k(5)+8=998 (remainder)

1125-200+5k+8=998

933+5k=998

5k=998-933=65

k=65/5=13

k=13

Answer 2

Answer:

P(x)=9x^3-8x^2+kx+8

g(x)=x-5

=5

p(x)=5

p(x)=9×(5)^3-8×(5)^2+k×5+8=998

=9×125-8×25+5k+8=998

=1125-200+5k+8=998

=935+5k=998

5k=998-935=65

k=65÷5=13

Therefore, k=13