The squares of a $(2^n-1)\times (2^n-1)$ chessboard are filled with $ 1$'s and $-1$'s. We say that such a configuration is acceptable if the value in each square is equal to the product of the values of its neighbors (squares with a common edge). How many acceptable configurations are there

step-by-step explanation:

the multiplicative inverse of a fraction a/b is b/a. for the multiplicative inverse of a real number, divide 1 by the number. for example, the reciprocal of 5 is one fifth 1/5 or 0.2, and the reciprocal of 0.25 is 1 divided by 0.25, or 4.

-2 is the right

c

-by-step explanation:

it would be c

60

step-by-step explanation:

every triangle measures a total of 120 degrees. you have to find angle c. we know that isosceles triangles angles are equal. 60 degrees plus 60 degrees gives you 120.