Answer:

Explanation:
zeroes are when you plug in that x value and get y=0
therefore if you set x = that number and solve for 0 you get a "function"
multiplying these together will yield the complete 3rd degree polynomial
x = 1
x-1=0
x=7
x-7=0
x=-4
x+4=0

If needed you could expand but I'm too lazy