Answer :
I don’t see a grid, but use FOIL:
First = x*x = x^2
Outer = x*-1 = -x
Inner = 1*x = x
Last = 1*-1 = -1
Add:
x^2 - x + x - 1
x^2 - 1
First = x*x = x^2
Outer = x*-1 = -x
Inner = 1*x = x
Last = 1*-1 = -1
Add:
x^2 - x + x - 1
x^2 - 1