Answer:
3rd option. The way you do it is just plug in negative x value let's say -8, plug it in then y would be a positive value. So that rules out first two options. Then plug in positive x value, y would be negative.
(a+b)^7= a^7+ 7a^7b+ 21 a^6b²+ 35a^5b³+ 35 a⁴b⁴+ 21 a³b^5 + 7a²b^6 + b^7
