Answer:
-3,-2,1
Explanation:
An x-intercept is where a function touches the x-axis on a graph, meaning that y = 0. When multiplying to get 0 from (x - 1)(x + 2)(x + 3), at least one of the parentheses has to be 0. It won't matter what number ends up in the other two parentheses as long as one of the three is 0 since anything times 0 is 0.
There are 3 ways to get one of the parentheses to be 0:
x - 1 = 0
x = 1
x + 2 = 0
x = -2
x + 3 = 0
x = -3