Giải các phương trình sau : x/2000+(x+1)/2001+(x+2)/2002+(x+3)/2004=5

x2000+x+12001+x+22002+x+32003+x+42004=5⇔x2000−1+x+12001−1+x+22002−1+x+32003−1+x+42004−1=0⇔x−20002000+x−20002001+x−20002002+x−20002003+x−20002004=0⇔x−200012000+12001+12002+12003+12004=0⇔x=2000