Question

Cho P(x)=100x¹⁰⁰+99x⁹⁹+98x⁹⁸+...+2x²+x.  Tinh P(1)

Answer 1

P(1)=100.1¹⁰⁰+99.1⁹⁹+98.1⁹⁸+...+2.1²+1

=100+99+98+...2+1

=>P(1)+P(1)=100+99+98+...2+1+100+99+98+...2+1

=>2P(1)=(100+1)+(2+99)+...(2+99)+(1+100)  (100 cặp)

2P(1)=101.100

2P(1)=10100

=>P(1)=10100:2

P=(1)=5050

Answer 2

P(1) = 100.1^100 + ... +2.1^1 + 1

     = 100 + 99 +98 +.. + 1 

      = (100+1).100:2 = 50.101 = 5050