Answer:
70
Step-by-step explanation:
If you use Pascal's Triangle, you will need 9 lines, since there are 9 terms in a binomial raised to the 8th power. Those 9 terms are:
1, 8, 28, 56, 70, 56, 28, 8, 1
The first expansion through the one we need are below (I hope you know how to use Pascal's Triangle!):
[tex]1(x^8)(y^0)+8(x^7)(y^1)+28(x^6)(y^2)+56(x^5)(y^3)+70(x^4)(y^4)+...[/tex]
