Pls explaing by tep by step

a = 3

Step-by-step explanation:

If (x+3) is a factor of f(x) = x³+ax²+x+3,

From remainder theorem,

When we substitute -3 into the expression, we equate to zero

That is,

F(-3) = 0

(-3)³+a(-3)²+(-3)+3 = 0

-27+9a-3+3 = 0

9a = 27

divide both sides by the coefficient of a

a = 27/9

a = 3

Hence the value of a = 3