\(x^5+x+1=x.\left(x^4+1+\frac{1}{x}\right).\)
x5 +x4 + x3 +x2 +x+1 - x4-x3 -x2= (x+1)( x4 +x2 -x3) - x2 = x2((x+1)(x2 -x +1) -1)
Các bạn làm sai rùi mình làm lại nè:
= x5 - x2 + x2 + x + 1
= (x5 - x) + (x2 + x + 1)
= x2(x3 - 1) + (x2 + x + 1)
= x2(x - 1)(x2 + x.1 + 1) + (x2 + x + 1)
= (x2 + x + 1).(x2(x - 1) + 1)
= (x2 + x + 1)(x3 - x2 +1)