Question

4

∑
i=1(x−1i)= (x-1(1) +(x-1(2)+(x-1(3)+(x-1(4)
I am struck I need some help. Did I expand the problem right?

Answer 1

except for some unbalanced parentheses, it's ok.

All those 1's are just confusing. I'd prefer
4
∑ (x−i) = (x-1)+(x-2)+(x-3)+(x-4) = 4x-10
i=1