Question

if minus 3 is a zero of a polynomial x cube + 3 X square + 20 X + k then find the value of k

Answer 1

Hola Friend ✋✋✋

x = - 3

p ( x ) = x³ + 3x² + 20x + k = 0

p ( - 3 ) = ( - 3 ) ³ + 3 × ( - 3 ) ² + 20 × ( - 3 ) + k = 0

- 27 + 27 - 60 + k = 0

k = 60

Hope it helps