ok so I feel really stupid right now cause I can't figure this out:

The graph of a cubic polynomial function has x-intercepts -3,-1,and 2. The graph also passes through the point A(1,-24)

Determine the function in the factored form a(x-r1)(x-r2)(x-r3) where r1 ect represents the roots algebraically

Umm How do you solve for thevalue? I know its vertical strech but can't figure it out.a

Oh and I know a=3 but I can't do it algebraically