Because a and b are reciprocal, a+b = 0; Because the absolute value of X is 1 and X is equal to plus or minus one, the square of X is equal to1; Because cd is reciprocal, c * d =1; And because x is equal to plus or minus one and c*d*x is equal to plus or minus one, the algebraic expression is 0+655. - 1 & gt； Or 0+ 1- 1, so the answer is 2 or 0.