SubArea: Polynomials and fractionsLevel: AProject ID: 2010001301Source Problem: 9000101601Accepted: 0Clonable: 1Easy: 0Expand \( (x-1)(1-x+x^2)(x+1)\).\( x^4-x^3+x-1\)\( x^4-x^3+2x^2+x-1\)\( x^4+x^3-x+1\)\( x^4+x^3-2x^2+x-1\)
