Question

(x+3) is a factor of 3x^3+ax^2-x-12​

Answer 1

Answer:

a=10

Step-by-step explanation:

3x³+ax²-x-12

take x+3=0

then x=(-3)

put x=(-3) into equation and equate it with zero.(remainder theorem)

so

3(-3)³+a(-3)²-(-3)-12

-81+9a+3-12=0

9a-90=0

9a=90

a=10