( x + 1 ) + ( x + 2 ) + ( x + 3 ) +.....+ ( x + 100 ) = 10100
1.Tìm x biết :
x+(x+1)+(x+2)+...+(x+100)=10100
\(\Rightarrow\dfrac{\left(x+100+x\right)\left(x+100-x+1\right)}{2}=10100\\ \Rightarrow101\left(2x+100\right)=20200\\ \Rightarrow2x+100=200\Rightarrow x=50\)
<=> 101x+(1+99)+(2+98)+....+(49+51)+100+50=10100
<=> 101x+5050=10100
<=> 101x=5050
<=> x=50
\(x+\left(x+1\right)+...+\left(x+100\right)=10100\)
\(\Leftrightarrow101x+5050=10100\)
\(\Leftrightarrow101x=5050\)
hay x=50
Tìm x khi biết:
x+(x+1)+(x+2)+...+(x+100)=10100
x + ( x + 1 ) + ( x + 2 ) + ... + ( x + 100 ) = 10100
( x + x + x + ... + x ) + ( 1 + 2 + .. + 100 ) =10100
101x + 5050 =10100
101x =5050
x =50
x + (x+1) + (x+2) + ... + (x+100) = 10100
=> 101x + (1 + 2 + 3 + ... + 100) = 10100
Áp dụng công thức tính dãy số ta có :
1 + 2 + 3 +...+ 100 = \(\frac{\left[\left(100-1\right):1+1\right].\left(100+1\right)}{2}=\frac{100.101}{2}=50.101=5050\)
=> 101x + 5050 = 10100
=> 101x = 5050
=> x = 50
Tìm x1, x2 ,x3,...,x100
Biết\(\dfrac{x_1-1}{100}=\dfrac{x_2-2}{99}=\dfrac{x_3-3}{98}=...=\dfrac{x_{100}-100}{1}\)
và x1+x2+x3+...+x100=10100
X+( x+1)+(x+2)+.......+(x+100)=10100
Giúp mình nhé
x + ( x + 1 ) + ( x + 2 ) + ... + ( x + 100 ) = 10100
x + x + 1 + x + 2 + ... + x + 100 = 10100
( x + x + x + ... + x ) + ( 1 + 2 + ... + 100 ) = 10100
101x + 5050 = 10100
101x = 5050
x = 50
Vậy x = 50
X + (X + 1) + (X + 2) + .... + (X + 100) = 10100
X + (X + X + ... + X) + (1 + 2 + .... + 100) = 10100
X + X x 100 + 5050 = 10100
X x 101 = 10100 - 5050
X x 101 = 5050
X = 5050 : 101
X = 50
x+28*x+3*x+.............+100*x=10100
tìm số tự nhiên x và y
x+(x+1)+(x+2)+...+(x+100-10100
x+(x+1)+(x+2)+...+(x+100)-10100(thiếu dấu ngoặc)
Tìm x , y
xy - 2x = 5
x + ( x + 1 ) + ( x + 2 ) + ... + ( x + 100 ) = 10100
M = \(\frac{9^2}{90}\)x \(\frac{10^2}{110}\) x \(\frac{11^2}{132}\) x ... x \(\frac{100^2}{10100}\)
\(M=\frac{9^2}{9.10}.\frac{10^2}{10.11}.\frac{11^2}{11.12}.....\frac{100^2}{100.101}\)
\(=\frac{9}{10}.\frac{10}{11}.\frac{11}{12}.....\frac{100}{101}=\frac{9}{101}\)
tìm x biết: 1+5+9+14+...+x=10100