Question

[Nguyễn Khang Duy]

Tìm x

a) \(\left(x-1\right)+\left(x-2\right)+\left(x-3\right)+.....+\left(x-100\right)=101\)

b)  \(x+2x+3x+....+100x=1000\)

c)  \(x+1+2\left(x+2\right)+3\left(x+3\right)+...+100\left(x+100\right)=101^2\)

d)  \(\frac{1+x}{1}+\frac{1+x}{2}+\frac{1+x}{3}+...+\frac{1+x}{30}=0\)

e)  \(\left(1+\frac{x}{1}\right)\left(2-\frac{x}{2}\right)\left(3-\frac{x}{3}\right)=0\)

BẠN NÀO BIẾT PHẦN NÀO THÌ GIÚP MIK NHÉ!

Thank!!

Answer 1

[QuocDat]

a) (x-1)+(x-2)+(x-3)+...+(-100)=101

(x+x+x+...+x)-(1+2+3+...+100)=101

=> 100x-5050=101

100x=101+5050

100x=5151

x=5151:100

x=5151/100