1864 is the answer for your question
1)Because if u add 8+4 which is 12 and u just leave the x with the 12 which is 12x which is ur answer.
2)if you multiply 4 and 2x or 4•2x which is 8x and you if u multiply 4 and 1 which is 4 and you are left with 8x+4 which is 12x.
The zeros of this function is when y = 0.
(x, 0) and (x,0)
Looking on the graph
It would be (3,0) and (6,0)
The solution is x = 3, x = 6